Home

Wooden Boat Restoration & Repair

1. 2 Sand the surface fair to clean bare wood Remove all old finishes and contaminants Open existing joints with a scraper saw or router and fill the joints with epoxy Repair with fiberglass tape if necessary as suggested in Section 5 3 1 Cut out severely damaged areas and scarf in new plywood if necessary as suggested in Section 5 3 2 Plan the layout of the new plywood sheets to avoid new joints falling over existing joints Apply an epoxy 406 mixture to both bonding surfaces with a roller Thicken the mixture to a catsup consistency to allow some penetration and still bridge any gaps between the surfaces If the surface is rough or uneven thicken the epoxy mixture to a mayonnaise consistency and apply with a notched spreader Clamp the sheet in position with an even pattern of temporary screws or staples Clean up excess epoxy at the joints Repeat the procedure with each sheet Allow the epoxy to cure thoroughly before removing temporary fasteners Sand the surface fair before final finishing 5 4 Molded or laminated veneer repairs Another option for skin covering uses strips of thin veneer instead of sheets of plywood Laminated boats were and are being built by gluing layers of thin veneers together over curved forms in effect building a sheet of plywood in the shape of a boat This technique has produced lightweight rigid hulls that aren t limited to the flat surfaces and hard chines of plywood
2. thick strips A thick deck will provide you with years of service in high traffic areas and it will keep the additional weight of a new teak deck to a minimum Strips should be between 1 and 2 wide with edges planed smooth and straight Leave the flat surfaces top and bottom rough sawn The rough texture left by the saw improves the bonding characteristics of the strip The remaining marks on the exposed surfaces will be sanded smooth after the new deck has been laid If you plan to mill your own stock select a plank width that makes the most efficient use of the raw stock Teak is generally available in 2 thick rough sawn planks you should get close to a 134 finished dimension from these planks Saw the stock so that the strips will be edge grained Figure 5 23 This will minimize expansion and contraction of the wood and make a more attractive even wearing surface than will slab grained strips Moisture content should be between 6 and 10 Install a teak deck as follows 4 Edge grained Strips r Figure 5 23 Thin edge grained strips provide an even wearing attractive and dimensionally stable deck Plan the pattern for the layout of the teak strips Place the first teak strips in the desired location and then mark reference location points on the strips and on the deck Abrade any smooth bonding surfaces with 5 0 grit sandpaper and remove sanding dust Wipe the planks with paper towels saturated wit
3. 205 B or 206 B 350 405 sq ft 462 520 sq ft 86 qt 81L 1 2 9a 4 55L 39 37 m 43 48 m2 98 gal 3 74 L 207 B or 209 B 370 430 sq ft 490 550 sq ft 1 32 qt 1 24L 13 98l 4 98 L 35 40 m 45 50 m 205 C or 206 C 1530 1785 sq ft 2040 2300 sq ft 94 gal 3 581 529 9al 20 L 149 465 m 190 213 m 4 35 gal 16 47 L 207 C or 209 C 5 8 gal 21 9 L 1675 1955 sq ft 2235 2520 sq ft 1 45 gal 5 49 L 7 98 121 155 180 m 207 233 m Fiberglass thickness per layer Product number 742 729 E TBs Filler epoxy proportion guide Fabric weight 4 02 6oz 9oz 1202 15 oz 22 oz Approximate mixed epoxy required to produce a cat Singler cost oro 017 020 03 on sup Mayonnaise or peanut butter consistency for thickness j i the various sized filler products at 72 F Mixtures will be thinner at higher temperatures Quantity of mixed epoxy required for Epoxy shelf life Package size Catsup Mayonnaise Peanut butter If the containers are kept consistency consistency consistency sealed when not in use WEST SYSTEM resin and hardeners should remain usable for many years Over time 105 Resin will thicken slightly and will therefore re quire extra care when mix ing Hardeners may darken with age but physical prop erties are not affected by color Mini Pumps may be left in containers during storage It is a good idea af
4. v How will the boat be used v What results are you looking for A quick repair a complete restoration or something in between v Are you prepared to commit the time and resources to get the results you re looking for v Is wood epoxy construction the best solution to your problem v How can wood epoxy construction be used effectively for your repair Depending on the answers to these questions we try to help the customer formulate a reasonable plan of action and determine how wood epoxy construction and WEST SYSTEM products might be used Some of the questions are relatively easy How was the boat built What are the boat s problem areas Other questions may be more difficult to define what is your commitment to repairing the boat Naturally the larger the boat the greater the damage or more thorough the restoration the more important this question becomes Wooden Boat Restoration amp Repair is set up to help you answer the above questions for yourself You owe it to yourself and the project not to shortchange the process but to consider each question carefully Only when you have reasonable answers to all the questions should the real job of repairing or restoring begin A careful analysis of these questions and perhaps a review of the manual and what a repair will involve can also help you decide whether or not to buy a particular older wooden boat in need of repair Introduction 2 Using the manual Wooden Boat Restora
5. Figure 7 1 Effect of color on surface temperature under sunlight The angle of the exposed surface to the sunlight For example a deck will receive much more direct radiation at high noon when the sun s destructive UV rays are most damaging than would cabin sides Highly glossy surfaces are more reflective of UV rays and thus less vulnerable than are dull surfaces no matter what the color Lighter colored woods are more reflective than darker colored woods just as lighter colored paints are far more reflective than are darker colors Figure 7 1 Thicker clear coatings last longer and offer more protection than thinner coatings Varnishes with large amounts of UV inhibitors last much longer than varnishes without this additive Modern two part polyurethane varnishes last longer than the more traditional phenolic varnishes Ahigh strength epoxy resin undercoating such as WEST SYSTEM 105 207 mixture when used as a saturation coat under a varnish provides a greater life span than the use of varnish alone A bonus is dramatically improved moisture resistance Gougeon Brothers Inc has studied the effect of these factors through many years of observation and experimentation with all types of finishes particularly clear finishes In the laboratory we have used a weathering machine to accelerate UV damage to coated surfaces so that we have direct comparisons between different products finish Protecting and Ma
6. 6 frames 21 gluing 65 hardware 43 joint repair 22 scarf joints in planks 30 splines in carvel planking 29 studs and threaded rods 46 Butt joints planks 31 C Carvel planking repair 27 Cleanup 56 Clear coating 51 Coating benefits of 6 for moisture protection 50 Commitment determining 3 Controlling cure time 60 Coverage coating 72 Cure stages 59 D Damage inspecting and locating 11 Dispensing epoxy 61 Disposal epoxy 56 Double planking repair 32 Dry rot cause 4 drilling and filling 15 filling with epoxy 14 filling with wood 14 repairing 13 E Epoxy coating 50 Evaluating damage 8 F Fairing technique 68 Fastener bonding 43 Fillers description 57 Fillets 67 Floors repair 23 Frames laminating 17 replacing 19 G Garboard repair 22 Glazing compound 53 H Hardeners 57 Hardware casting 45 Hardware installing 43 Hazards 55 Historical value 3 Inspecting the boat 8 J Joint repair 22 Joint strength 65 K Keel bolt repair 25 Keel repair 25 L Laminated skin repair 37 Laminating 66 Laminating frames 17 Lapstrake plank repair 32 Linear polyurethanes 52 M Manual overview 2 Mini pumps using 61 0 Open time 59 P Paints 52 Plastic bonding to 65 Plywood skin repair 33 Pot life 60 Precautions health 55 Preparation for bonding 63 Index 78 Primers 53 Problem solving 73 R Removing epoxy 63 Repa
7. At this point the epoxy has reached most of its ultimate strength so clamps can be removed It will continue to cure over the next several days at room temperature Anew application of epoxy will no longer chemically link to it so the surface of the ep oxy must be properly prepared and sanded before recoating to achieve a good mechani cal secondary bond See Surface Preparation 8 4 1 8 3 2 Understanding and controlling cure time Open time and cure time govern much of the activity of building and repairing with ep oxy Open time dictates the time available for mixing application smoothing shaping assembly and clamping Cure time dictates how long you must wait before removing Using WEST SYSTEM Epoxy 60 clamps or before you can sand or go on to the next step in the project Two factors deter mine an epoxy mixture s open time and overall cure time hardener cure speed and ep oxy temperature Hardener speed Each hardener has an ideal temperature cure range Figure 8 1 At any given tempera ture each resin hardener combination will go through the same cure stages but at dif ferent rates Select the hardener that gives you adequate working time for the job you are doing at the temperature and conditions you are working under The product guide and container labels describe hardener pot lives and cure times Pot life is a term used to compare the cure speeds of different hardeners It is the amount of time a specific mass
8. Bingham Bruce THE SAILOR S SKETCHBOOK Camden ME Seven Seas 1983 Butler Paul and Marya FINE YACHT FINISHES FOR WOOD AND FIBERGLASS BOATS Camden ME International Marine Publishing Co 1987 Chapelle Howard L BOATBUILDING New York W W Norton amp Co 1969 Duffett John BOAT OWNER S GUIDE TO MODERN MAINTENANCE New York W W Norton amp Co 1985 Editors of WoodenBoat Magazine WOODEN BOAT AN APPRECIATION OF THE CRAFT Reading MA Addison Wesley Publishing Co 1982 Gougeon Brothers Inc THE GOUGEON BROTHERS ON BOAT CONSTRUCTION 4th Edition Bay City MI Gougeon Brothers Inc 1985 McIntosh David C Bud HOW TO BUILD A WOODEN BOAT Brooklin ME WoodenBoat Publications Inc 1987 Monk Edwin MODERN BOAT BUILDING New York Charles Scribner s Sons 1973 Skoog Jim CRUISING IN COMFORT Camden Me International Marine Publishing Co 1986 Spurr Daniel SPURR S BOAT BOOK UPGRADING THE CRUISING SAILBOAT Camden ME Seven Seas 1990 Steward Robert M BOATBUILDING MANUAL Camden Me International Marine Publishing Co 1980 Temple Mark O THE COMPLETE STEP BY STEP BOAT REPAIR amp RESTORATION HANDBOOK Blue Ridge Summit PA TAB Books Inc 1981 Trefethen Jim WOODEN BOAT RENOVATION Camden Me International Marine Publishing Co Index A Adhesive fillers 58 Aluminum bonding to 65 Assessing feasability 2 Bonding butt joints in planks 31 for stiffness
9. Dry the surface with pa per towels to remove the dissolved blush before it dries on the surface Sand any re maining glossy areas with 80 grit sandpaper Wet sanding will also remove the amine blush If a release fabric is applied over the surface of fresh epoxy all amine blush will be removed when the release fabric is peeled from the cured epoxy and no additional sanding is required Epoxy surfaces that have not fully cured may be bonded to or coated with epoxy with out washing or sanding Before applying coatings other than epoxy paints bottom paints varnishes gelcoats etc allow epoxy surfaces to cure fully then wash and sand Hardwoods Sand with 80 grit paper Sand white oak with 60 grit Teak oily woods Wipe with acetone 15 minutes before coating The solvent dries the oil at the surface and allows epoxy to penetrate Be sure the solvent has evaporated be fore coating Porous woods No special preparation needed If surface is burnished possibly by dull planer blades sand with 80 grit paper to open pores 65 Using WEST SYSTEM Epoxy Steel lead Remove contamination sand or grind to bright metal coat with epoxy then sand fresh epoxy into surface Recoat or bond after first coat gels Aluminum Sand and prepare with 860 Aluminum Etch Kit Polyester fiberglass Clean contamination with a silicone and wax remover such as DuPont Prep Sol 3919S Sand with 80 grit paper to a dull finish Plastic Ad
10. Maples gS GOUGEON Table of Contents 1 Introduction 1 1 Assessing the feasibility of repair and restoration 1 2 Why wooden boats fail 1 3 WEST SYSTEM epoxy for wooden boat repair 1 4 Key steps in repair and restoration 2 Inspecting and Evaluating 2 1 Understanding the Structure 2 2 Inspecting and locating damaged areas 3 Repairing Localized Dry Rot 2 1 Excavate and fill 2 2 Drilling and filling 2 3 Reinforcing 4 Repairing the Structural Framework 3 1 Laminating beams frames and stems 3 2 Removal and replacement of frames 3 3 Removing and replacing a damaged section 3 4 Installing sister frames or doublers 3 5 Joint repairs 3 6 Repairing garboards 3 7 Keel repair 5 Repairing Hull and Deck Planking 4 1 Carvel planked hulls and laid plank decks 4 2 Lapstrake Planked Hulls 4 3 Plywood hulls and decks 4 4 Molded or laminated veneer repairs 4 5 Installing a teak veneer deck oOo oo A N 11 13 15 16 iy 19 20 21 22 22 25 27 32 33 37 41 6 Installing Hardware 6 1 Fastener bonding 6 2 Hardware bonding 6 3 Casting epoxy bases for hardware 6 4 Bonding studs 6 5 Removable hardware 6 6 Removing bonded hardware 7 Protecting and Maintaining Wooden Boats 6 1 Sunlight and protective coatings 6 2 Applying the final epoxy coatings 6 3 Clear finish coatings 6 4 Paint 6 5 Repairing dings and cracks 6 6 Ventilation for longevity 8 Using WEST SYSTEM Epoxy 8 1 Ep
11. diagrams and photographs 002 550 Fiberglass Boat Repair amp Maintenance Acomplete guide to repair fiberglass boats with WEST SYSTEM Epoxy Includes illustrated procedures for structural reinforcement deck and hull repair hard ware installation keel repair and teak deck installation 002 650 Gelcoat Blisters Diagnosis Repair amp Prevention A guide for repairing and preventing gelcoat blisters in fiberglass boats with WEST SYSTEM Epoxy Includes an analysis of the factors that contribute to blis ter formation and illustrated steps for preparation drying repairing and coating for moisture protection 002 150 Vacuum Bagging Techniques A step by step guide to vacuum bag laminating techniques for bonding wood core materials and fabrics with WEST SYSTEM Epoxy Discusses theory molds equipment and techniques used to build composite structures 002 740 Final Fairing amp Finishing Techniques for fairing wood fiberglass and metal surfaces Includes fairing tools materials and a general guide to finish coatings 002 892 Basic Application Techniques A video primer on WEST SYSTEM Epoxy Products and their use Includes safety procedures and application tips for coating bonding and fairing VHS 20 min 002 894 Fiberglass Repair with WEST SYSTEM Brand Epoxy A guide to structural repair on fiberglass boats Covers repairs to cored and non cored panels and how to apply gelcoat over epoxy repairs VHS 20 min 002 896 Gelcoat Bl
12. p ueds e uo weaq papeo Jayuao payoddns Adus e woy painseaw Ayoyseja Jo snjnpoyy JUaJUOD aINIsIOU ZT 9 paysnipe are auy puosas y ul asou euayew aad jo s s W01 are saisads Yyoea 10 au jsly y Ul sanjeg suawpads pouresb jyBregs eap ews uo s sa Jo synsay I p LY dd p26 O q UaSuysem Po Buguug yuewUsaAcd ZZ ON YOoqpuRyY ammu By jo juawpedeg Si yooqpunpy poom Aloyeloge y sjonpoig 198104 Woy payeyxy O 0 T O81 OIT L TOT 6ST 008 ZI E9 OZO T 062 T OLb S 8 OT TST 000 TT Ly yeol So OTS OLE OST T 08S O19 S v6 LSI 0020 Ov bZ ose osz 092 ogg 0L9 g9 EZTI 00L S Le eqs anade EZ ogs O 0 T oes oZE S SOT S T 003024 ot bZ OLE OOT 099 OVI OLS bL 90 T 00b S 8E yoriq aonudg VN o0E T vIST 080 OT O ZI LTZ 00P 8T VN VN Ovo p66 VN G6ES 06 Lo T 008 6 6c uey gI 08E OTe 006 Ott 008b 89 pel 009 8 Ge ZI 062 osz 089 ozz OY os 66 006b bE pym Uld vE 028 0Lb OIS T 096 OLp 8 BIT 86 T 00S PI 69 Se 06S O e Ov0 T O8b Oze b 68 6ST 00 8 Ss jearSuo aug oE 069 OLP 06 T 062 OST vor 6L T 008 Z1 TS o ost 0o92 098 06 Oss o8 ob T 00E L Ly AOO UG VN 08E VN VN VN 006 DIT O0E L Le uooqeg umoyo VN 0E9 VN VN VN 0L6 9 LU 9 T OOT Z1 VN 099 VN VN VN OSb b 38 0st 009 8 ey paa yep HULIN VN org VN 062 T VN 0 9 9 6L ISI 009 TT YN 002 VN OLE T WN orst 96 8z1 00e 6 Gp sempuoy Aueboyew VN 06S VN 060 T VN OSL S VN LoT O0E TT by VN 00S
13. F Grab the edge with a pair of pliers and pull up on the cloth while heating just ahead of the separation On large areas use a utility knife to score the glass and remove in narrower strips Resulting surface texture may be coated or remaining epoxy may be removed as follows Removing cured epoxy coating Use a heat gun to soften the epoxy 200 F Heat a small area and use a paint or cabinet scraper to remove the bulk of the coating Sand the surface to remove the remaining material Provide ventilation when heating epoxy 8 4 Basic techniques The following basic techniques are common to most repair or building projects re gardless of the type of structure or material you are working with 8 4 1 Surface preparation Whether you are bonding fairing or applying fabrics the success of the application de pends not only on the strength of the epoxy but also on how well the epoxy adheres to the surface to which it is being applied Unless you are bonding to partially cured ep oxy the strength of the bond relies on the epoxy s ability to mechanically key into the surface That is why the following three steps of surface preparation are a critical part of any secondary bonding operation For good adhesion bonding surfaces should be CLEAN Using WEST SYSTEM Epoxy 64 DRY SANDED 1 Clean 2 Dry Bonding surfaces must be free of any contaminants such as grease oil wax or mold re lease Clean contaminated sur
14. Paint Protecting and Maintaining Wooden Boats 52 durability while retaining a high gloss UV resistant surface Be sure the surface is properly prepared see Section 8 4 1 1 Thoroughly mix the two part polyurethane varnish in the proper ratio For major applications over large surface areas always use the 800 Foam Roller which will give a more uniform application in less time This means runs are less likely during application and you will have more time to do touch up Use a high quality brush with a tapered tip 2 to 3 wide depending on the intricacies of the surface to be coated During application the roller will leave a slightly stippled surface with some air entrapped in the coating In most instances this stipple will flow out and the bubbles will pop on their own to leave a smooth high gloss surface upon cure In some conditions you will need to brush out the rolled on coating to assist the leveling process Do this by lightly brushing the surface with smooth even strokes as soon as possible after you have applied the varnish Be aware that the time available to perform this tipping off will vary by climate Cooler temperatures should allow 5 to 10 minutes to tip off a newly applied coating with no difficulty hot dry conditions will allow you less time For health reasons we do not recommend spraying two part polyurethane Inhalation of fumes dust vapors and droplets must be avoided Spraying marine pa
15. Service U S Department of Commerce Reprint AD 490 100 Springfield VA p 13 2 Corrections to the strength properties should be made successively for each 1 change in moisture content until the total change has been covered For each 1 decrease in moisture content the strength is multiplied by 1 P where P is the percentage correction factor shown in the table and expressed as a decimal For each 1 increase in moisture content the strength is divided by 1 P 3 Negative values indicate a decrease in work to maximum load for a decrease in moisture content Oven dry weight of veneers of varying thicknesses by species oe LG Ounces per square foot veneer Air dry Specific moisture Veneer thickness in inches Species gravity content 1 16 1 8 3 16 1 4 Ash white 0 58 8 9 3 02 6 04 9 05 12 06 Birch yellow 0 63 9 6 3 28 6 56 9 84 13 12 Cedar Spanish 0 37 7 3 1 92 3 85 5 77 7 70 Cedar red 0 31 1 83 3 67 5 49 7 34 Fir Douglas 0 51 6 2 2 65 5 30 7 96 10 6 Mahogany African 0 46 8 0 2 39 4 78 7 17 9 57 Mahogany Central American 0 49 7 9 2 55 5 10 7 66 10 20 Spruce Sitka 0 38 8 9 1 98 3 96 5 94 7 94 1 Extracted from Michelon and Devereaux p 163 2 Based on oven dry weight and air dry volume 76 Wood data ZT ye Jo ueaiB uaym aunjon pue Aup uano uaym jyBiem uo paseq st Ayers syed JuayUuoD ainysjow YOTL H Burseasour Aq Uuolayep 1eays JO 2a ja ay JO p pP UOI aq ULI SNMPOW ay T O pT JO OL yzd
16. Staple the veneer so it lies flat against the surface at about a 35 diagonal Figure 5 21 Adjust the angle as necessary to allow the veneer to lie flat along its full length Figure 5 22 Bond the second layer of veneers in the opposite diagonal to the first layer Bond the remaining veneers of the first layer Trim the second veneer to fit tight against the first and lie flat against the surface The ends of the veneer may have to be tapered if the surface is a compound curve Bond and staple the second veneer in place Continue trimming and bonding veneers in each direction from the first veneer Sand the surface fair after the epoxy cures thoroughly Staples should be removed before sanding unless they are a non corroding type which may be left in Repeat the process on the second layer Figure 5 22 Begin with the first veneer about midpoint at a 35 diagonal in the opposite direction to the first layer Trim and bond the remaining veneers Repeat the process on the remaining layers Remove the staples after the last layer has cured Sand the surface fair and prepare it for final finishing 41 Repairing Hull and Deck Planking 5 5 Installing a teak veneer deck Thin strips of teak bedded in a thick epoxy graphite layer give you an authentic teak deck that is both durable and low in maintenance Although strips of up to 1 4 thickness may be used the effects of dimensional change can be limited by using thinner
17. VN 08 VN OSL E VN br oos Tb pas yS ueneg L9 VN VN oerz o9L T 0126 BSS IT 000 02 ol bl WN VN 02S T Obs 08s LEZ LSI 000 TT vo ArO DIH TE OTL ObE OETI 008 Ove L 66 S6 I 00b ZI 8b 9 00S 00 006 O8E 08Z OL 9G T O0LL Sp yseoo y sejSnoq LI Ose ozz 066 09b 09S P 8S ITT 00S L ZE LI 09g OEZ OLL Ove OLL S Os p6 ooz S TE pai uiasom iepa 8z 0 9 00b OLE T 0 L 0S2 9 T6 OLT 0OL ST ey 1 08E O8T ors ooe OvT DL OE T 009 9 6E POO HOdq Iepag l OE ove 058 Ole 096 8t 08 0059 TE SI oez obz 029 oEZ 066 T LG oo 002 r 62 aym WiayYoN Wepad 66 08s 09 OET T 0z9 org9 yoI gb I OOT II pb LZ obb OEE Ors OSE 0SO E 26 PUI 0079 ov ueysejy Iepady GS 09 T 026 0gs T 0L6 OLT 8 802 TOZ 009 9T Z9 8b O82 O amp P OITT OEP OSEE Tor OST 00 s SF moja yong OOT SII 00 oor S08 T 8s 006 2 LT unpau es eg Eb oZE I Ov6 0S6 T O9T T OIL 9I pL I O0P ST 09 8E 096 06S O8E T 049 066 991 bbl 009 6 SS aym ysy sayou spunog isd isd isd isd yaur a1qn gt isd isd eneb s p dg Jad spunog uow aypadg amey ueb O yybuags yjbuagys yu UOT yjbuags peo zAplonseya mydn ajajdwo2 ut Iem pua d ayisua wnu Buueays oid ye ssas Burysnso wmnuwixew jo jo snes doip i d peo XBUU ULBIB o umwxew ueb5 Jaqy ureiB o wnunxew uteiD O HOM snmpow Ssnmpow Jo 1 481 y ssaupiey Jeinoipuadiad o paed Jemmpuadi d o jaesed Bulpuaq aPIS uolsual qeays uolssaidwod uolssaidwio7 Bulpuag IVIG pedu 77 Additional reading Additional reading
18. and between the new and old floors Bond the new floors and blocking to the keel and frames Figure 4 10 Wet out all mating surfaces and end grain with resin hardener mixture Apply thickened epoxy 406 filler Clamp in position until epoxy cures Allow the epoxy to cure thoroughly before removing clamps and proceeding with the next step Drill two vertical holes at each hull frame through the blocking and at least 3 into the keel The diameter of the holes should be larger than the threaded rods selected for this repair Cut a piece of stainless or hot dipped galvanized threaded rod to match the depth of each hole The threaded rod should be the same diameter as the original keel bolts Wet out one or two holes at a time with unthickened resin hardener mixture Allow the epoxy to penetrate the end grain inside the hole Repairing the Structural Framework 24 0 we New Blocking Remove several planks each side Figure 4 10 Bond new floors and blocking to the keels and Figure 4 11 Bond threaded rod through the blocking and at least frames 3 into the keel 9 Fill the wet out holes half full of thickened epoxy 404 or 406 filler Apply thickened epoxy to the threaded rod filling the threads 10 Push the coated rod to the bottom of the filled hole Figure 4 11 Fill the holes to the top as necessary Clean up excess epoxy before it cures 4 6 2 Reinstalling garboards The keel floors and frames are now per
19. and gap Fill screw holes with epoxy Sy screw with epoxy 404 423 he Sand flush 1 8 1 4 THICK STRIPS veneers 1 4 3 4 THICK STRIPS planks Figure 5 24 Sheet metal screws with large washers will clamp the strips in position until the epoxy 404 graphite mixture cures thor oughly 7 Place the remaining strips several at time following the same procedure 8 Allow the epoxy to cure between 8 and 24 hours before removing the screws and washers If you wait any longer than this it will become much harder to break the screws free Tighten the screw slightly 5 before backing it out If you have difficulty removing a screw heat the head with a soldering gun s cutter tip While the screw is still hot try to unscrew it again Repeat until you are successful 9 Fill the screw holes with epoxy 404 graphite mixture A syringe loaded with the mixture will speed the process 10 Sand the surface with a reciprocating sander and 50 grit sandpaper to level the epoxy and teak surfaces Sand until the saw marks are removed from the teak surface Fine sand with 80 grit sandpaper and then finish with 120 grit The teak surface may be left natural or finished with a marine grade teak oil Note If planks thicker than 14 are used do not fill between the planks with thickened epoxy Instead remove squeezed out epoxy between planks and allow to cure Remove the screws and washers and sand the top surface of the planks fair Fill the jo
20. and shaping of low areas so they blend with the surrounding surfaces and appear fair to the eye and touch After major structural assembly has been completed final fairing can be easily accomplished with WEST SYSTEM epoxy and 407 or 410 low density fillers 1 Prepare the surface as you would for bonding Section 8 4 1 Sand smooth any bumps or ridges on the surface and remove all dust from the area to be faired 2 Wet out porous surfaces with unthickened epoxy Figure 8 14 3 Mix resin hardener and 407 Low Density or 410 Microlight filler to a peanut butter consistency fg M Figure 8 14 Wet out porous surfaces before applying Figure 8 15 Trowel the thickened epoxy fairing com thickened fairing compound pound into the voids and depressions with a plastic spreader 4 Trowel on the thickened epoxy mixture with a plastic spreader working it into all voids and depressions Smooth the mixture to the desired shape leaving the mixture slightly higher than the surrounding area Figure 8 15 Remove any excess thickened epoxy before it cures If the voids you are filling are over 1 2 deep apply the mixture in several applications or use 206 Slow Hardener or 209 Extra Slow Hardener depend ing on ambient temperature 5 Allow the final thickened epoxy application to cure thoroughly 6 Sand the fairing material to blend with the surrounding contour Figure 8 16 Begin with 50 grit sandpaper if you have a l
21. be faired by using an epoxy filler fairing compound if the surface is to be painted Any additional fairing done after the final coating should receive several additional coats over the faired area Note A third alternative a variation of both methods is to apply the fabric after a wet out coat has reached an initial cure Follow the first three steps of the Wet Method but wait until the epoxy cures dry to the touch before positioning the fabric and continuing with Step 3 of the Dry Method Apply the fabric before the first coat reaches its final cure phase Refer to Section 7 Protecting and Maintaining Wooden Boats for procedures on bar rier coating and applying finish coatings WEST SYSTEM product estimating guides 72 WEST SYSTEM product estimating guides Group size quantities and coating coverage WEST SYSTEM epoxy resin and hardeners are packaged in three Group Sizes For each con tainer size of resin there is a corresponding sized container of hardener and a corresponding mini pump size When purchasing resin hardener and mini pumps be sure all containers are labeled with the same Group Size letter A B or C Hardener Mixed Saturation Coat Buildup Coats quantity quantity quantity Porous Surfaces Non Porous Surfaces 205 A or 206 A 90 105 sq ft 120 135 sq ft 43 pt 20L 12041151 og 5 gma 11 12 5 m 1 qt 94 L 207 A or 209 A 1 3 qt 90 105 sq ft 120 135 sq ft 66 pt 31 L 1 26 L 9 10 m 11 13 m
22. bedding material and eventually allow moisture into the fastener hole Moisture can quickly penetrate the end grain of the hole weakening the fastener s grip even further This overview of a boat s structure highlights some of the problems you are likely to face as a wooden boat owner While these problems may be daunting they don t have to be fatal One of the beauties of wood is its resilience With a little resuscitation and the proper protection your boat can begin a long and low maintenance second life If you would like a more thorough discussion of boat structure consult the books listed in Appendix Additional reading page 77 2 2 Inspecting and locating damaged areas The first phase of repair involves inspecting and locating damaged areas Even though damage may be obvious finding all the hidden damage will probably require some dismantling Because hidden damage from trapped moisture is a major problem with wooden boats a thorough job of dismantling is important A careful inspection will allow you to make better decisions about what repair procedures to follow as well as let you know just how big a job you are in for Tops of Beams Floor frame Keel Joints Frame Sockets A and Frame Ends Frame plank Joints Y_ Keel garboard Joint Figure 2 4 Look for dry rot at joints and areas of standing water and poor air circulation Inspecting and Evaluating 12 Begin your inspection as follows 1 Su
23. fairing compounds stir in as much 407 or 410 as you can blend in smoothly for easy sanding the thicker the better Be sure all of the filler is thoroughly blended before the mixture is applied 63 Using WEST SYSTEM Epoxy until the desired consis tency is reached Figure 8 7 Blend in L oc 5 a small handfuls or scoops D Pa of the appropriate filler Additives Additives are used to give epoxy additional physical properties when used as a coating Although additives are blended with mixed epoxy in the same two step process as fill ers they are not designed to thicken the epoxy Follow the mixing instructions on the individual additive containers 8 3 5 Removing epoxy Removing uncured or non curing epoxy Removed uncured epoxy as you would spilled resin Scrape as much material as you can from the surface using a stiff metal or plastic scraper warm the epoxy to lower its viscosity Clean the residue with lacquer thinner acetone or alcohol Follow safety warnings on solvents and provide adequate ventilation After recoating wood surfaces with epoxy it s a good idea to brush the wet epoxy in the direction of the grain with a wire brush to improve adhesion Allow solvents to dry before recoating Removing fiberglass cloth applied with epoxy Use a heat gun to heat and soften the epoxy Start in a small area near a corner or an edge Apply heat until you can slip a putty knife or chisel under the cloth about 200
24. falls between frames the backing plate should run from frame to frame When replacing longer sections of planking a backing plate is only required at the ends Butt p 7 Repairing Hull and Deck Planking 32 Wet out all mating surfaces with resin hardener mixture Apply thickened epoxy 403 or 406 peanut butter consistency to the mating surfaces including the surface of the backing plate facing the plank Install the backing plate s to the back of the planking Temporarily clamp the backer in position with screws staples or nails Install the new plank section Clamp the section in position with screws staples or nails Fill remaining openings in seams with thickened epoxy Remove clamps and fair the surface after the epoxy has cured thoroughly 5 1 5 Double Planking A A WD Repairs to double planked boats involve removing the outer layer of planking repairing the inner layer following the procedures already described in Section 5 1 and then replacing the outer layer of planks Removing both layers of planking is desirable in that it allows you to examine the planks thoroughly and seal them completely in epoxy If you wish to coat the inside of the hull with epoxy you need to remove both layers of planking clean and strip them of paint and rebond them to the framing timbers Remember you can only encapsulate the boat with epoxy if all of the surfaces especially the contact su
25. filler to the mixture until it reaches a peanut butter consistency the more filler added the stiffer and easier it will be to sand 2 Allow the wet out coat to gel before applying the fairing material to vertical surfaces Blush formation is typical Remove with water See 8 4 1 Special preparation page 64 Red color will not affect epoxy performance May not be suitable for clear coating or in exposed areas where color is not desired Allow the final epoxy coat to cure thoroughly Allow several days if necessary for slow hardeners at cooler temperatures Warm the epoxy if possible Paint incompatible with ep oxy 1 Use a different type of paint Some single part polyurethanes are incompatible with the hardener If unsure test for compatibility on a coated piece of scrap material 2 Use 207 Hardener Epoxy surface not thor oughly prepared Batch is too large Remove the amine blush and sand the surface thor oughly before applying paints or varnishes See 8 4 1 Special preparation page 64 1 Mix smaller batches 2 Transfer the mixture to a container with more surface area immediately after mixing Temperature too warm for the hardener Surface tension causes ep oxy film to pull away from pinhole before it gels Air trapped in the wood es capes through coating out gassing as the wood s temperature is rising Use 206 Slow or 209 Tropical hardener in very warm weather A
26. fit the opening Match the 8 to 1 bevel on each end Figure 5 6 4 Make the new piece of wood slightly thicker than the original planking Excess material inside or outside the hull can be planed off after the glue has cured Wet out the mating surfaces with resin hardener mixture Recoat the scarfed surfaces as necessary until the end grain is fully saturated 31 Repairing Hull and Deck Planking Figure 5 6 Replace a section of plank using scarf joints 5 Apply thickened epoxy 403 or 406 peanut butter consistency to one side of each bonding area 6 Clamp the scarfed section in place with temporary screws or staples until the epoxy has cured Corrosion resistant screws can be left in if the pilot holes were wet out with epoxy 7 Remove clamps and fair the surface after the epoxy has cured thoroughly Butt joint method The butt joint is an alternative to the scarf joint for repairing damaged planks in place Although not as strong as the scarf it is considerably easier to do Butt joints should be staggered adjacent planks should not end at the same place To repair a damaged plank section using butt joints 1 Remove the damaged portion of the plank using a circular saw hand saw saber saw or chisel 2 Cuta replacement piece of wood for the opening and a piece for a backing plate Figure 5 7 A backing plate will be required behind each butt joint unless the joint falls on a frame When the repair section
27. hardener before mixing to speed the cure in cool weather 3 Switch to a faster hardener if possible PROBLEM Clear coating turned cloudy Fairing compound ep oxy 407 or 410 mixture sags and is difficult to sand Waxy film appears on surface of cured epoxy The hardener has turned red after several years storage Paint or varnish will not set up over epoxy Epoxy became very hot and cured too quickly Pinholes appear in ep oxy coating over abraded fiberglass or ep oxy Bubbles formed in coat ing over bare wood or other porous material POSSIBLE CAUSES Moisture from condensation or very humid conditions reacts with amines in un cured hardener 74 Problem solving guide SOLUTION 1 Wash and sand cured coating to remove blush Cloudiness may appear in the amine blush at the surface or throughout the coating 2 Use 207 Hardener for clear coating applications 3 Use 205 or 206 Hardeners for clear coating only in dry conditions 4 Use 207 Hardener for laminating thin veneers that may allow epoxy to bleed to the surface especially when vacuum bagging Entrapped air from aggres sive roller application Fairing material not thick enough Amine blush forms as part of the curing process Moisture in contact with hardener and metal con tainer Epoxy not completely cured 1 Apply coating at warmer temperature thinner ep oxy 2 Apply epoxy in thin coats 1 Add more
28. is a light amber color that will tint wood slightly darker and warmer similar to varnish 3 1 mix ratio 209 Extra Slow Hardener Used for general bonding barrier coating and fabric ap plication in extremely warm and or humid conditions Provides approximately twice the pot life and working time as 206 Slow Hardener and adequate pot life up to 110 F 43 C Also used at room temperatures when a long pot life and working time are required 3 1 mix ratio Hardener Selection Guide HARDENER TEMPERATURE RANGE F CURE SPEEDS at room temperature GUN S 35 RESIN HARDENER USE Room Temp POTLIFE OPENTIME CURETO mw Gi RiP P ere oe 100g cupful thin film thin film 9 12 60 70 6 8 minutes minutes hours General bonding fabric ap 20 25 90 110 10 15 plication and barrier coating minutes minutes hours General bonding fabric ap plication and barrier coating 22 27 110 130 12 18 minutes minutes hours 40 50 3 4 20 24 minutes hours hours Epoxy cures faster in warmer temperatures and in thicker applications Epoxy cures slower in cooler temperatures and in thinner applications coating General bonding fabric ap plication and barrier coating Clear fabric application and Figure 8 1 Select a hardener for its intended use and for the cure speed best suited for your job in the temperature range you are working in 8 2 2 Fillers Throughout this manual we will refer to epoxy or resin hardener mixture meanin
29. low density filler peanut butter consistency Use a spreader to apply the thickened epoxy slightly overfilling low areas on the surface Allow the mixture to cure thoroughly before fairing 5 3 3 Replacing installing plywood 3 4 You may install new plywood over exposed frames or over existing hull or deck surfaces Plywood used as the primary skin bonded directly to the frames may be laid out with scarfed joints falling directly over the frames or with butt joints over backing plates between the frames Scarfed joints offer a cleaner appearance from the interior The frame spacing and size of the boat determine the thickness of the plywood The amount of compounding determines whether the total thickness can be applied in one layer or in multiple layers Apply thinner plywood in multiple layers if one layer is too thick to bend over a curved surface Apply a primary plywood skin as follows Prepare plywood panels scarf joints and beam surfaces Plan the panel layout and order of assembly so that the scarf on the following sheet lies over the scarf on the previous sheet Figure 5 14 Wet out the bonding surfaces of the plywood and frames Wet out scarfs on the ends of adjoining sheets Apply a coat of thickened epoxy 406 mixture to the bonding surfaces of the frame and the scarf of the previous sheet Lay the sheet in position over the frames Align the scarf joint to avoid overlapping Figure 5 14 Plan the panel
30. of mixed resin and hardener remains a liquid at a spe cific temperature A 100g mass mixture in a standard container at 72 F Because pot life isa measure of the cure speed of a specific contained mass volume of epoxy rather than a thin film a hardener s pot life is much shorter than its open time Epoxy temperature The warmer the temperature of curing epoxy the faster it cures Figure 8 3 Curing epoxy s temperature is determined by the ambient temperature plus the exothermic heat generated by its cure Ambient temperature is the temperature of the air or material in contact with the ep oxy Air temperature is most often the ambient temperature unless the epoxy is applied to a surface with a different temperature Generally epoxy cures faster when the air temperature is warmer Exothermic heat is produced by the chemical reaction that cures epoxy The amount of heat produced depends on the thickness or exposed surface area of mixed epoxy Ina thicker mass more heat is retained causing a faster reaction and more heat The mix ing container shape and mixed quantity have a great affect on this exothermic reaction A contained mass of curing epoxy 8 fl oz or more ina plastic mixing cup can quickly generate enough heat to melt the cup and burn your skin However if the same quan tity is spread into a thin layer exothermic heat is dissipated and the epoxy s cure time is determined by the ambient temperature The thinner the layer
31. on the surface Figure 5 10 Wet out the cleaned out seam and sanded area with resin hardener mixture Recoat the seam with epoxy as necessary as it is absorbed into the end grain of the plywood Inject or work epoxy between any delaminated veneers that are still sound Apply thickened epoxy 403 or 406 mayonnaise consistency to the seam Use a plastic spreader to force the thickened epoxy into the wet out seam and smooth the excess mixture along the joint Work the thickened mixture into any voids and between wet out delaminated veneers Apply a layer of fiberglass tape in the depression along the joint Figure 5 11 727 Biaxial Tape 4 wide is ideal for this joint Use the spreader to work epoxy into the fabric and remove the excess Apply additional layers if desired in the same manner A PN gt Figure 5 10 Sand a valley along the joint to allow for fiberglass Figure 5 11 Apply fiberglass tape over the prepared joint tape 35 Repairing Hull and Deck Planking Place new layers 2 to either side of the previous layer so the edges don t fall directly on top each other For details on applying fiberglass cloth see Section 8 4 5 Apply thickened epoxy 407 or 410 low density filler peanut butter consistency to the joint Use a plastic spreader to trowel on and shape the thickened mixture slightly higher than the plywood surface Section 8 4 4 Allow to cure thoroughly and sand fair 5 3 2 Replacing dam
32. size Bond the new frame back into place permanently as previously described 4 2 Removal and replacement of frames Often a framing member is too damaged to be repaired and replacement is the best option Replace a damaged frame as follows Support the hull and remaining structure before removing frames If necessary leave some damaged frames to maintain the shape replacing them after new frames are installed Remove all fasteners holding the frame Cut the damaged frames into sections if necessary to remove them Laminate the replacement frame using the instructions in Section 4 1 1 You may also cut or steam bend a frame to match the original if you choose Trim the frame to fit Prepare the frame and contact area for bonding Avoid bonding to anything you intend to remove later Install the frame Wet out all contact areas with epoxy Apply a thickened epoxy 406 mixture to one side of each contact area Repairing the Structural Framework 20 Temporary Brace Lm Plank removed for clamping Figure 4 3 Install the new frame in the same position as the old frame Braces or screws may be used to hold the frame until the epoxy cures 5 Clamp the frame in position until the epoxy cures If the fasteners of the old frame are to be reused bond the fasteners with epoxy 4 3 Removing and replacing a damaged section Often damage to a frame is limited to a small section or the frame may be too difficult t
33. stems Frames can be cut from solid stock or steam bent if you plan to restore the structure exactly If you steam bend frames be sure to allow plenty of time for the frame to dry out before bonding However laminated frames have many advantages over steam bent frames both structurally and in ease of fabrication Whole and partial frames are made of multiple thin layers of wood to duplicate the shape and dimension of the damaged frame Sections 4 2 4 3 and 4 4 There are no limitations to the size of frame that can be laminated Laminating may be the only practical or economical way to duplicate large structural members as large timber becomes more scarce The new frame can be laminated in a simple jig made from a pattern or in some cases directly in place in the hull Keep in mind the following when selecting wood for laminating frames 1 Choose wood strips that are the same or similar species as the original frame 2 Use wood strips thin enough to bend easily into the shape of the original frame Be sure all of the strips collectively can bend to shape When fewer thicker strips are used for a given thickness of frame more stress is induced resulting in less strength and more 4 5 Repairing the Structural Framework 18 springback in the curved frame Using more thinner strips results in a curved frame with greater strength and less springback but requires more labor and epoxy to build Use thinner strips especially with hard
34. the fasteners until a small amount of hole provides enough clamping pressure to hold the hardware in position epoxy squeezes from the joint until the epoxy cures 1 Drill an oversized pilot hole to increase the amount of exposed wood area that the epoxy around the fastener will bond to This may be much larger than the fastener twice the fastener diameter for example Drill the hole 2 3 to 3 4 the depth of the fastener 2 Drill a normal sized pilot hole at the bottom of the oversized hole to the full length of the fastener Figure 6 1 This allows the bottom threads of the fastener to bite into the wood fiber so the fastener will stay in proper position until the epoxy cures 3 Prepare the hardware by washing the contact surface of the base with solvent to remove any contamination Abrade the contact surface with a wire brush or 50 grit sandpaper to allow the epoxy to key into the surface 4 Fillthe holes to the top with epoxy Allow the epoxy to soak into the exposed end grain of the wood for a few minutes If the hole remains filled after 5 minutes remove the epoxy with the syringe 5 Coat the bottom contact surface of the hardware with unthickened epoxy Wire brush or sand the wet epoxy into the surface with 50 grit sandpaper Sanding the base coated with epoxy will expose the epoxy directly to fresh metal with no chance for the metal to oxidize 6 Inject a non sagging epoxy 404 or 406 mixture into the hole Use enough m
35. two or three coats to completely fill the weave of the cloth and to allow for a final sand ing that will not affect the cloth Wet method An alternative is to apply the fabric or tape to a surface coated with wet epoxy As men tioned this is not the preferred method especially with large pieces of cloth because of the difficulty removing wrinkles or adjusting the position of the cloth as it is being wet out However you may come across situations when this method may be useful or necessary 1 Prepare the surface Section 8 4 1 Pre fit and trim the cloth to size Roll the cloth neatly so that it may be conveniently rolled back into position later Roll a heavy coat of epoxy on the surface 4 Unroll the glass cloth over the wet epoxy and position it Surface tension will hold most cloth in position If you are applying the cloth vertically or overhead you may want to wait until the epoxy becomes tacky Work out wrinkles by lifting the edge of the cloth and smoothing from the center with your gloved hand or a spreader Apply a second coat of epoxy with a foam roller Apply enough epoxy to thoroughly wet out the cloth Remove the excess epoxy with a spreader using long overlapping strokes The cloth should appear consistently transparent with a smooth cloth texture Follow steps 7 8 and 9 under the dry method to finish the procedure Any remaining irregularities or transitions between cloth and substrate can
36. utility knife Figure 8 19 Trim overlapped cloth if desired as follows Figure 8 19 Trim excess cloth when the epoxy reaches its initial cure phase The wet out cloth will be dry but flexible and will trim easily with a sharp utility knife oe 4 as a Place a metal straightedge on top of and midway between the two overlapped edges b Cut through both layers of cloth with a sharp utility knife Figure 8 20 c Remove the topmost trimming and then lift the opposite cut edge to remove the overlapped trimming Figure 8 21 d Re wet the underside of the raised edge with ep oxy and smooth into place Figure 8 20 Trim overlapping fabric using a metal Figure 8 21 Remove the topmost trimming Then lift straightedge and a sharp utility knife for a flush butt the opposite cut edge to remove the overlapped trim joint ming The result should be a near perfect butt joint eliminating double cloth thickness A lapped joint is stronger than a butt joint so if appearance is not important you may want to leave the overlap and fair in the unevenness after coating 9 Coat the surface to fill the weave before the wet out reaches its final cure stage Figure 8 22 Follow the procedures for epoxy barrier coating under Section 7 2 It will take 71 Using WEST SYSTEM Epoxy Figure 8 22 Apply the first coat of un thickened epoxy to fill the weave of the cloth before the wet out coat reaches its final cure phase
37. wood on A Larger cavities should be filled with wood wherever possible This method restores the small piece of wood original strength of the wood The procedure involves carving a dutchman to the shape shaped to closely fill the of the void and bonding it in place with epoxy as follows void in a larger piece of 1 i Prepare the dutchman Use the same kind of wood if possible Carve the cavity to a wood geometric shape if necessary to make shaping the plug easier Bevel the sides of the cavity The longer the bevel on the sides running across the grain the stronger the repair Figure 3 3 An 8 to 1 bevel 8 long for every 1 deep or greater will be close to the original strength of the wood Check the dutchman for fit Thickened epoxy will fill a fairly large gap so the fit doesn t have to be perfect Prepare the surfaces for bonding Section 8 4 1 2 Wet out the bonding surfaces of the cavity and the plug with resin hardener mixture 3 Apply thickened epoxy adhesive filler 406 404 or 403 mayonnaise consistency to the cavity surfaces Using the mixing stick apply enough of the thickened mixture to fill any gaps 4 Insert the plug into position Thickened epoxy should squeeze out of the joint 5 Clamp the plug into position Weights or staples may be used to hold the plug until the epoxy cures Remove excess epoxy before it begins to cure 6 Allow to cure thoroughly before removing clamps or sanding 15 Repairi
38. 002 970 Wooden Boat Restoration amp Repair A guide to restore the structure improve the appearance reduce the maintenance and prolong the life of wooden boats with WEST SYSTEM Brand epoxy Contents 1 Introduction Assess the feasibility of restoration or repair with WEST SYSTEM epoxy 2 Inspecting and Evaluating Analyze the structure for loss of stiffness dry rot damage and repair strategies 3 Repairing Localized Dry Rot Repair small areas damaged by dry rot 4 Repairing the Structural Framework Repair or replace damaged frames beams stems sheer clamps and keels 5 Repairing Hull and Deck Planking Repair damaged carvel lapstrake plywood and molded veneer planking 6 Installing Hardware Install hardware to increase load carrying capacity and eliminate deck leaks 7 Protecting and Maintaining Wooden Boats Applying protective coatings for finishing and preserving wooden boats 8 Using WEST SYSTEM epoxy Use WEST SYSTEM products safely and effectively Appendix WEST SYSTEM product estimating guides Problem solving guide Wood data Additional reading Index BRAND Wooden Boat Restoration amp Repair Catalog Number 002 970 6th Edition A guide to restore the structure improve the appearance reduce the maintenance and prolong the life of wooden boats with WEST SYSTEM Brand epoxy The techniques described in this manual are based on the handling techniques and physical properties of WEST SYSTEM Brand epo
39. Add extra mixture if necessary for shaping or to fill any voids Remove any excess before it cures Allow the epoxy to cure thoroughly Tap the hardware with a mallet to remove it from the base Clean the bottom of the hardware and the top of the cast base with solvent to remove the mold release Sand both bonding surfaces with 50 grit paper Installing Hardware 46 D WINCH ASSEMBLED Tempora oe Epoxy C Interface Shape epoxy mixture fair ga one with deck C ans Plate if deck is thin Figure 6 3 Hardware casting is an excellent method for installing a piece of hardware that is not flush to the deck such as a winch 10 Sand the cast base to the desired final finish Begin with 50 grit sandpaper or a file if the base is extremely irregular Finish with 80 grit sandpaper 11 Bond the hardware to the cast base using the hardware bonding procedure in section 6 2 Figure 6 3c Drill oversized and standard pilot holes for the fasteners through the cast base Allow to cure thoroughly before applying loads to the hardware Apply three coats of resin hardener mixture to the base before final finishing 6 4 Bonding studs Bond threaded rods or studs into the substrate instead of bolts or screws and attach the hardware with nuts This variation is appropriate for many engine motor or machine installations Coat the base with wax mold release to make the hardware removable Although the hardware is not bo
40. Prepare the surface as you would for bonding Section 8 4 1 2 Position the cloth over the surface and cut it several inches larger on all sides If the sur face area you are covering is larger than the cloth size allow multiple pieces to overlap by approximately two inches On sloped or vertical surfaces hold the cloth in place with masking or duct tape or with staples 3 Mix a small quantity of epoxy three or four pumps each of resin and hardener 4 Pour a small pool of resin hardener near the center of the cloth 5 Spread the epoxy over the cloth surface with a plastic spreader working the epoxy gently from the pool into the dry areas Figure 8 17 Use a foam roller or brush to wet out fabric on vertical surfaces Properly wet out fabric is transparent White areas indi cate dry fabric If you are applying the cloth over a porous surface be sure to leave enough epoxy to be absorbed by both the cloth and the surface below it Try to limit the amount of squeegeeing you do The more you work the wet surface the more min ute air bubbles are placed in suspension in the epoxy This is especially important if you plan to use a clear finish see note page 70 You may use a roller or brush to apply ep oxy to horizontal as well as vertical surfaces r y lt See cad me Figure 8 17 Spread the epoxy from the center of the Figure 8 18 Squeegee away excess epoxy before the fabric toward the edges with a plastic spreader first ba
41. a gel state to a solid state Cure time is shorter when the epoxy is warmer Cure time is longer when the epoxy is cooler a _ Gel Solid Liquid Initial cure Finalcure Open time phase phase gt IS c Tacky RECOAT Epoxy Temperature Minimum Recommended Temperature Cure time after mixing 1 Liquid Open time Open time also working time or wet lay up time is the portion of the cure time after mixing that the resin hardener mixture remains a liquid and is workable and suitable for application All assembly and clamping should take place during the open time to assure a dependable bond 2 Gel Initial cure The mixture passes into an initial cure phase also called the green stage when it begins to gel or kick off The epoxy is no longer workable and will no longer feel tacky Dur ing this stage it progresses from a soft gel consistency to the firmness of hard rubber You will be able to dent it with your thumb nail The mixture will become tack free about midway through the initial cure phase While it is still tacky anew application of epoxy will still chemically link with it so the surface may still be bonded to or recoated without special preparation However this ability diminishes as the mixture approaches the final cure phase 3 Solid Final cure The epoxy mixture has cured to a solid state and can be dry sanded and shaped You should not be able to dent it with your thumbnail
42. a lot of time if you can avoid carving intricate pieces of wood to fit hard to reach areas but a solid epoxy patch weighs more and costs more per pound than wood Also you are limited by the epoxy s exothermic reaction to about a layer using 205 hardener in one application A larger volume would heat up enough to cause foaming and significant weakening of the epoxy Although you may use slower hardener and or apply the epoxy in multiple layers to avoid exotherm there are practical limits to the size of cavity that can be filled with solid epoxy Repairing Localized Dry Rot 14 3 1 1 Filling with epoxy Small cavities are most conveniently filled with solid thickened epoxy as follows 1 Prepare the surface Section 8 4 1 Be sure the area is thoroughly dry 2 Wet out the repair area with the resin hardener mixture see Two step bonding page 65 3 Fill the cavity with epoxy thickened with a high density 406 404 or 403 filler to a peanut butter consistency Trowel the mixture into the void with a plastic spreader or mixing stick Figure 3 2 Smooth the mixture flush with the surface and remove any excess before the mixture begins to cure 4 Allow the mixture to cure thoroughly before sanding _ Dutchman 8 to 1 Minimum NN Scarf Angle Figure 3 2 Trowel thickened epoxy into smaller voids Figure 3 3 Bond a dutchman into larger cavities Bevel the sides of the cavity and the dutchman to match 3 1 2 Filling with
43. aces without first wetting out the surfaces with neat resin hardener We recommend that you thicken the epoxy no more than is necessary to bridge gaps in the joint the thinner the mixture the more it can penetrate the surface and that you do not use this method for highly loaded joints or for bonding end grain or other porous surfaces Laminating The term laminating refers to the process of bonding numbers of relatively thin layers like plywood veneers fabrics or core material to create a composite A composite may be any number of layers of the same material or combinations of different materials Methods of epoxy application and clamping will differ depending on what you are laminating Because of large surface areas and limitations of wet lay up time roller application is the most common method for applying epoxy A faster method for large surfaces is to simply pour the resin hardener mixture onto the middle of the panel and spread the mixture evenly over the surface with a plastic spreader Apply thickened mixtures with an 809 Notched Spreader Using staples or screws is the most common method of clamping when you laminate a solid material to a solid substrate An even distribution of weights will work when you are laminating a solid material to a base that will not hold staples or screws such as a foam or honeycomb core material 67 Using WEST SYSTEM Epoxy Vacuum bagging is the ideal clamping method for laminating a wid
44. aged plywood sections Figure 5 12 Cut out the damaged area and grind a minimum 8 Figure 5 13 Clamp a new repair patch in position with staples 8 to 1 Minimum Bevel Sections of plywood panels may suffer from impact or dry rot damage and can be repaired without replacing the whole panel The damaged section can be cut out anda replacement section bonded in without losing any panel strength Replace small plywood panel sections as follows Cut the damaged section out of the panel Use a circular saw or reciprocating saw to cut the smallest square or rectangle that encloses all of the damage Check the extent of damage on the interior of the panel Scarf or step the edges of the opening a Grind a scarf on the edges with a disc sander Figure 5 12 Grind a minimum 8 to 1 bevel back from the edges of the opening If the panel plywood is 2 thick the bevel should extend at least 4 from the edge of the hole on each side b Milla step on the edges of the hole with a router Use a straight fluted bit to machine a step or steps in the panel round the opening The width of each step should be eight times the step thickness Steps are convenient when laminating several layers of thinner plywood to equal the thickness of the damaged panel Make each step equal to the thickness of one replacement layer to 1 bevel on all sides of the opening or screws 3 Fabricate the replacement panel using the same or equivalent plywood a
45. aluable for new boat construction also make it ideal for repairing older boats The techniques in this manual are designed to take maximum advantage of epoxy s properties within the limits of an existing older structure WEST SYSTEM epoxy is a structural marine adhesive formulated to bond to wood Epoxy is used in the construction of new wooden boats that are both lightweight and very rigid Bonding joints with epoxy provides greater bonding area than mechanical fasteners and totally seals and protects joints from moisture Joints bonded with WEST SYSTEM epoxy are often stronger than the wood being bonded Bonding with epoxy requires little clamping pressure with staples and screws often used to hold the pieces together until the epoxy cures As an adhesive WEST SYSTEM epoxy is ideal for repairing existing damage and reducing flexing in the structure WEST SYSTEM epoxy is unequaled as a moisture barrier Epoxy s ability to protect wood structures from water has made modern wooden boats nearly immune to dry rot To a degree this protection can be applied to older wooden boats by keeping the moisture content below the point where dry rot can survive WEST SYSTEM epoxy has excellent gap filling qualities This eliminates the need for precise fits and a lot of clamping pressure WEST SYSTEM epoxy is easy to use and versatile WEST SYSTEM products include a complete line of epoxy materials and supplies developed to meet a wide range of buil
46. alue Condition of the boat Obviously the worse the condition of the boat the more work needed to repair it While in theory no boat is beyond restoration you should probably think about looking for another boat if less than 60 percent of the boat is salvageable Size of the craft Reconstruction difficulty increases with boat size This is because larger craft experience higher loads Boat timbers are proportional to boat size and epoxy is usually just on a surface or perimeter This means epoxy strengths and effects can be overwhelmed by proportionately larger wood mass effects Dimensional changes can be the result of moisture passage or temperature cycling as well as stresses from boat use Also larger craft may have more areas that are difficult or impossible to access Construction method You need to understand the construction method originally used to build the boat and the level of difficulty involved with repair of different construction methods The following provides a general guide to the logistical and practical ease of reconstructing craft built using different construction methods with the easiest listed first Plywood soft and hard chine Strip plank Laminated hot and cold molded Lapstrake Carvel single Carvel double If you have little experience with boat repair reading the rest of this manual can give you some sense of the work involved in particular projects You will also need to make a thorough evalu
47. ance to sunlight salt spray and other weathering factors They possess outstanding abrasion resistance and hardness that can equal or surpass that of polyester gel coat Best of all LP paints bond well to a cured WEST SYSTEM epoxy surface Until recently most LP paint systems were designed for spray application and application difficulties somewhat restricted their marine use However several of the large paint companies have now developed brushable LP systems which we have applied with rollers and brushes on several recent projects While brushing may not be quite as fast as spraying the preparation time required for brushing is much less Thus there is not a great time difference between the two methods and in some situations brushing could even be faster 53 Protecting and Maintaining Wooden Boats Safety Unfortunately LP systems pose a significant health hazard mainly due to spraying action LP systems contain small amounts 1 to 2 of a highly toxic material called isocyanate When sprayed this isocyanate is atomized Most manufacturers recommend use of a supplied air hood to prevent breathing or contacting any contaminated air Brush application of LP paint systems reduces the isocyanate problem to almost nothing because without atomization the isocyanate does not escape into the atmosphere to be inhaled Thus you can avoid the major obstacle to using LP systems by applying the material with a brush instead of spraying However
48. ank Leave just enough material at the back of the seam to prevent epoxy from passing through to the inside Figure 5 1 Use a circular saw to clean out plank seams Figure 5 2 Cut a bevel on the end of zah plank i 5 Clean out each seam by running the saw along the batten Figure 5 1 Check the depth and width of the cut Clean out the butt joints at the ends of the plank as well Chisel a shallow bevel on the end of the planks 1 4 deep x 2 back from the edge Figure 5 2 The bevel increases bonding area and reduces stress at the joint A router with a straight fluted bit also will work to clean out seams Select a bit wide enough to shave both planks The router will get into tighter places than the circular saw but the bits dull quickly often break and are expensive to replace A chisel can be used in tight spots to carve a V groove where a saw or router will not work A scraping or reefing tool for cleaning out seams can be made from a mill file as shown in Appendix C or you may invent your own tool or method for cleaning the seams Remember the object is to clean out the old caulk and expose clean wood on the facing edge of each plank for good bonding 29 Repairing Hull and Deck Planking 5 1 2 Filling the seams with wood After machining a clean gap between two planks bond a spline of suitable wood into the gap The spline should be of the same species or stronger than the planking Remember S
49. ardener may be reclaimed for use DO NOT use saw dust or other fine cellulose materials to absorb hardeners DO NOT dispose of hard ener in trash containing saw dust or other fine cellulose materials spontaneous combustion can occur Clean resin or mixed epoxy residue with lacquer thinner acetone or alcohol Follow all safety warnings on solvent containers Clean hardener residue with warm soapy wa ter Clean 207 Hardener residue with alcohol Dispose of resin hardener and empty containers safely Puncture a corner of the can and drain residue into the appropriate new container of resin or hardener DO NOT dispose of resin or hardener in a liquid state Waste resin and hardener can be mixed and cured in small quantities to a non hazardous inert solid CAUTION Pots of curing epoxy can get hot enough to ignite surrounding combusti ble materials and give off hazardous fumes Place pots of mixed epoxy in a safe and ventilated area away from workers and combustible materials Dispose of the solid mass only if curing is complete and the mass has cooled Follow federal state or local disposal regulations 8 2 Epoxy products This section provides a short description of WEST SYSTEM resin hardeners and fill ers Refer to the current User Manual amp Product Guide for complete information on all WEST SYSTEM products 8 2 1 Resin and hardeners Resin 105 Resin A clear light amber low viscosity epoxy resin that can be cured in a wid
50. as well as weather protection All of these factors work together to provide good ventilation If you have questions about options we suggest you consult the books listed in Appendix Additional reading page 77 55 Using WEST SYSTEM Epoxy 8 Using WEST SYSTEM Epoxy This section is designed to help you understand and safely handle WEST SYSTEM epoxy products and to provide the basic techniques used in most repair and building operations Refer to the WEST SYSTEM User Manual Product Guide for more complete product information 8 1 Epoxy safety Epoxies are safe when handled properly To use WEST SYSTEM epoxies safely you must understand their hazards and take precautions to avoid them Hazards The primary hazard associated with epoxy involves skin contact WEST SYSTEM Res ins may cause moderate skin irritation WEST SYSTEM Hardeners are corrosive and may cause severe skin irritation Resins and hardeners are also sensitizers and may cause an allergic reaction similar to poison ivy Susceptibility and the severity of a reac tion varies with the individual Although most people are not sensitive to WEST SYS TEM Resins and Hardeners the risk of becoming sensitized increases with repeated contact For those who become sensitized the severity of the reaction may increase with each contact The hazards associated with resins and hardeners also apply to the sanding dust from epoxy that has not fully cured These hazards decrease a
51. ation of the boat s structure as described in Section 2 or hire a surveyor Try to talk to others who have undertaken similar projects Understanding your own level of commitment to the project and developing a realistic plan for repair and restoration are necessary for your project to succeed Introduction 4 1 2 Why wooden boats fail The nature of wood and the techniques required to build boats in the past have contributed to both the beauty and the misfortune of wooden boats The amount of work necessary to maintain wooden boats tarnished their appeal and lack of maintenance resulted in many beautiful wooden boats being devoured by the elements Wooden boats may vary widely in age and condition but most suffer in some degree from two common problems 1 2 1 Loss of stiffness 1 2 2 Dry rot Much of the appeal of wooden boats lies in the boatbuilder s skill in joining many individually crafted pieces of wood into a single structure and loss of the original stiffness is a major cause of a boat s deterioration The forces acting on a boat during normal use put each joint under a continual strain For example when a wave or swell passes under a boat it lifts the hull unevenly Waves supporting the hull under the ends force the sides of the hull apart a wave supporting the hull in the middle forces the sides together Waves or swells crossing at an angle can lift the bow in one direction and the stern in another causing a twist that pull
52. bilges an open interior layout watertight deck openings and effective ventilators all work together to provide good ventilation If you have questions about options we suggest you consult the books on boatbuilding outfitting and storing your boat listed in Appendix Additional reading page 77 Inspecting and Evaluating 8 2 Inspecting and Evaluating To evaluate the condition of your boat you need to answer the first two questions listed in Section 1 What type of construction is the boat What condition is the boat in Understanding how your boat was built can help you assess the damage that has occurred A knowledge of the structure will make you alert to less obvious damage and aid you in determining whether the damage has compromised the integrity of the boat To assess the condition of your boat you will need to inspect it thoroughly This probably will involve some dismantling 2 1 Understanding the Structure Evaluating the soundness of your boat involves recognizing how well the individual and combined structural components are still doing their job Most wooden boats are characterized by a structural framework covered with a protective skin 2 1 1 The structural framework While they may vary in size shape and function most wooden boats have common structural elements Figure 2 1 The elements form the overall framework and work together with the planking to carry loads The heavier framework of conventionally planked
53. boats Using veneers for skin repairs offers the advantage of being able to conform to any curved shape especially compound curves This advantage can be used for repairs in several ways Veneers can be used to patch small sections of laminated hulls that are too curved for a plywood patch On a larger scale laminating layers of veneer over an existing plywood or carvel planked hull is an excellent method of adding a lot of stiffness to a hull or deck without removing the existing skin More detailed information about laminating veneers as a building technique can be found in 002 The Gougeon Brothers On Boat Construction Repairing Hull and Deck Planking 38 5 4 1 Laminating a curved patch in place Laminating a patch for repairing a molded panel combines two procedures already covered repairing damaged plywood sections and laminating frames Laminating a curved panel section in a large damaged area requires temporary backup stringers to act as a jig Laminate the patch in place as follows 1 Remove the damaged section of the panel Define the area of damage Use a circular saw or reciprocating saw to cut the smallest square or rectangle that removes all of the damage Figure 5 15 Check the extent of damage on the interior of the panel as well of J 7 A SA f u ia Figure 5 15 Remove the damaged section Figure 5 16 Bevel the edges and fasten temporary stringers to the back of the open tic to prevent bonding View from insi
54. boats is designed to provide most of the structure s stiffness During the building after the boat is launched or when she is hauled for service the various structural members carry and distribute the concentrated and heavy loads of the boat More contemporary boats with plywood skins may have less or lighter framework Look at each of the elements of your boat s structure to see whether it still has the strength to carry the load it was designed to carry The keel is the backbone of most boats Traditionally the heaviest most rigid element in the structure it provides a foundation for the rest of the structure Like all components the keel should not only be strong enough to resist bending but also solid enough to hold the fasteners that transfer loads from adjoining parts Frames and floor timbers run athwartships at regular intervals along the keel The symmetrical frames give the hull shape while the floors distribute the loads from the ballast keel or engine stringers out over even more of the planking 9 Inspecting and Evaluating Deck Beams a Short Beams io Ss Sn Sheer Clamp Shelf Se Floor A Bilge Stringer Keelson sts r Carvel Planking Keel A NN Garboard Plank Carlin Frame Figure 2 1 Typical structural framework Deck beams connect the tops of each pair of hull frames Collectively they tie the two halves of the hull together preventing the hull from spreading or collapsing and supporti
55. brown color and can be used to tint other fillers 406 Colloidal Silica For general bonding gap filling high strength bonds and fillets A practical and versatile smooth textured filler It can be used alone or mixed with other fillers to improve workability and smoothness Cures to an off white color Fairing fillers 407 Low Density Filler A blended microballoon based filler used to make a fairing compound that is easy to sand or carve while still being reasonably strong on a strength to weight basis Cures to a reddish brown color 410 Microlight A very low density filler for creating a light easily worked fairing compound 410 spreads smoothly and sands very easily when cured Not recom mended under dark colored paint or on other surfaces subject to high temperatures Cures to a light tan color See Appendix Estimating Guides for WEST SYSTEM products for additional filler se lection information Filler Selection Guide USES ADHESIVE FILLERS FAIRING FILLERS r Highest density Lowest density Resin Hardener mixture Highest strength Easiest sanding thickened with a Filler 404 406 403 405 407 410 Use description Desired characteristics Migh density Colloidal Silica Microfibers Filleting Blend Low density Microlight Bonding Hardware Increased fastener in terface and hardware load capability Maxi mum strength General Bonding Join parts with epoxy thickened to create a structural gap fill
56. chieved with a good hull design The flexible approach implies that a wooden boat is at its best just before it falls apart Dry rot is another cause of wooden boat damage It is a natural decay process caused by the growth of brown rot a type of fungus that feeds on the cellulose in wood fiber Along with severe loss of strength dry rot causes the wood to discolor crack across the grain and shrink Dry rot isa misleading term since wood must be damp for the fungus to exist In fact all of these four conditions must be present for the fungus to survive v FOOD an adequate supply of wood fiber Y MOISTURE moisture content of the wood at or near the fiber saturation point above 20 v OXYGEN v WARMTH 76 to 86 F 24 to 30 C is ideal for rot growth rot can be active in temperatures as low as 50 F 5 Introduction The many joints in a wooden boat are potentially ideal environments for dry rot Wherever wood contacts wood air circulation and evaporation will be reduced If a leak occurs the moisture level of the wood at a joint can easily reach the fiber saturation level and still allow enough oxygen for rot growth Wood preservatives attempt to control rot by poisoning the food supply This approach has had only limited success and does nothing to address the problem of loss of wood strength due to high moisture content 1 3 WEST SYSTEM epoxy for wooden boat repair The properties of WEST SYSTEM epoxy that make it v
57. d the basic techniques for surface preparation bonding bonding with fillets laminating fairing and applying woven cloth and tape which are discussed in Section 8 Sections 3 7 of the manual provide detailed procedures for particular types of repair and can be used in whatever order your repair requires 13 Repairing Localized Dry Rot 3 Repairing Localized Dry Rot Repairing small areas of dry rot may be the most common repair to wooden boats Most structures have many small isolated areas with poor ventilation that can trap moisture and harbor dry rot These pockets of dry rot often can be repaired in place by excavating the damage and filling the cavity 3 1 Excavate and fill Remove all wood noticeably damaged by rot making sure to extend well away on both sides of the apparent damage Use a chisel to excavate all of the weak crumbly wood leaving a clean cavity with solid wood exposed on all sides Figure 3 1 Use a wire brush to remove any remaining soft wood around the cavity The size of the exposed cavity will determine which of two filling methods is the most appropriate You can fill small cavities with solid thickened epoxy and fill larger cavities by bonding in a dutchman wood shaped to fill the cavity Figure 3 1 Use a chisel to excavate a cavity that extends beyond all of the damaged wood The decision to fill the cavity with solid epoxy or with wood is based on convenience practicality and economics You can save
58. de of ing hull 2 Scarf the edges of the opening with a disc sander Grind a minimum 8 to 1 bevel back from the edges of the opening If for example the panel plywood is 1 2 thick the bevel should extend at least 4 from the edge of the hole on each side 3 Fasten temporary stringers to the back side of the opening with screws Figure 5 16 The stringers should be strong enough and spaced closely enough to hold the veneers to the proper shape Cover the stringers with plastic to prevent bonding Figure 5 17 4 Staple the first layer of veneers over the stringers Run the veneers diagonally approximately 35 from vertical Scarf the ends of the veneers to match the scarf on the edge of the opening Bond these first layer veneers only where the scarfs make contact using the bonding procedure in Section 8 4 2 Use 403 or 406 filler to thicken the epoxy to a mayonnaise consistency Figure 5 18 Bond the second layer in the oppo site diagonal to the first layer completed matching the skin thickness 39 Repairing Hull and Deck Planking 5 Bond the second layer of veneers after the first layer has reached a partial cure or a full cure with sanding Figure 5 18 Run the veneers diagonally in the opposite direction about 35 from vertical Remove the staples only in the area under the veneer being bonded Coat the face of the new veneer and the contact area of the first layer including bot
59. ding and maintenance needs Both amateurs and professionals can tailor the epoxy system to meet the specific needs of the project WEST SYSTEM epoxy and repair information is backed by over thirty years of experience Introduction 6 Gougeon Brothers Inc has been manufacturing WEST SYSTEM epoxy since 1969 and has earned a reputation for excellence in formulating practical long lasting and affordable epoxies for marine construction New sail and power boats constructed with WEST SYSTEM products have dominated many classes of competition and families are cruising throughout the world in seaworthy craft built restored or maintained with WEST SYSTEM epoxy Gougeon Brothers Inc has the construction experience research and testing and qualified technical staff to answer specific repair questions and provide expert guidance to those using WEST SYSTEM products 1 4 Key steps in repair and restoration The three key steps in formulating a plan for the use of epoxy in the repair or restoration of wooden boats are Bonding for stiffness Coating for moisture protection Ventilating for longevity 1 4 1 Bonding for stiffness RE The issue of stiffness is fundamental in our thinking about epoxy in marine structures As mentioned the loss of stiffness in the original structure is one of the problems leading to the boat s deterioration When you use epoxy to repair or restore a boat you are introducing stiffness into the structure If you are p
60. ds The garboard is the plank which meets the keel or deadwood It sometimes separates from the keel allowing water to leak into the boat If this leak recurs season after season even after the seams are thoroughly caulked you may have a serious problem to 23 Repairing the Structural Framework attend to The wood keel may be pulling away from the floors the wood timbers that tie the frames into the keel or the floors may no longer be tied effectively to the frames To check for this Inspect the area where the floors attach to the frames Look for signs of movement between the floors and the frames Figure 4 9 Inspect the area where the floors attach to the keel Look for a gap between the floors and keel Figure 4 9 Inspect the floors keel and frames for gaps or signs of movement 4 6 1 Repairing floors If gaps exist between the frame and floors or the floors and the keel they will cause the garboard seam to open The following repair procedures will correct the problem and permanently attach the floors to the frames and keel 1 Remove the garboards and one or two additional planks from each side of the hull Prepare the keel floors and frames Remove old paint or varnish and sand to bare wood Dry the area thoroughly Cut new floors to fit opposite the old floors on the opposite side of the frames They may be laminated or cut from solid stock Cut filler blocks that fit between the frames
61. e temperature range to yield a high strength rigid solid which has excellent cohesive properties and is an outstanding bonding adhesive and moisture vapor barrier WEST SYSTEM 105 Resin is formulated for use with four different WEST SYSTEM harden ers Use the Hardener Selection Guide Figure 8 1 to select the hardener most suited for your application 57 Using WEST SYSTEM Epoxy Hardeners 205 Hardener Used for general bonding barrier coating and fabric application For mulated to cure at lower temperatures and to produce a rapid cure that develops its physical properties quickly at room temperature 5 1 mix ratio 206 Slow Hardener Used for general bonding barrier coating and fabric application Formulated for a longer working and cure time or to provide adequate working time at higher temperatures 5 1 mix ratio Note 205 Fast and 206 Slow Hardener may be blended for intermediate cure times Always maintain the proper 5 part resin to 1 part hardener ratio Do not mix 205 or 206 5 to 1 ratio Hardeners with 207 or 209 3 to 1 ratio Hardeners 207 Special Coating Hardener Formulated specifically for barrier coating and fabric application where clear finish is desired 207 contains a UV stabilization additive but still requires long term UV protection with paint or varnish It provides good physical properties for bonding but it is more difficult to thicken and less cost effective for this purpose than 205 or 206 hardener 207
62. e range of materials Through the use of a vacuum pump and plastic sheeting the atmosphere is used to apply perfectly even clamping pressure over all areas of a panel regardless of the size shape or number of layers For detail information on vacuum bagging refer to 002 150 Vacuum Bagging Techniques 8 4 3 Bonding with fillets A fillet fiP it is a cove shaped application of thickened epoxy that bridges an inside corner joint It is excellent for bonding parts because it increases the surface area of the bond and serves as a structural brace All joints that will be covered with fiberglass cloth will require a fillet to support the cloth at the inside corner of the joint The procedure for bonding with fillets is the same as normal bonding except that instead of removing the squeezed out thickened epoxy after the components are clamped in position you shape it into a fillet For larger fillets add thickened mixture to the joint as soon as the bonding operation is complete before the bonding mixture becomes tack free or any time after the final cure and sanding of exposed epoxy in the fillet area 1 Bond parts as described in 8 4 2 Bonding 2 Shape and smooth the squeezed out thick epoxy into a fillet by drawing a rounded filleting tool mixing stick along the joint dragging excess material ahead of the tool and leaving a smooth cove shaped fillet bordered on each side by a clean margin Some excess filleting material will remain ou
63. e span The first phase of finish breakdown is loss of gloss so surface gloss retention is essential for coating longevity Clear coating breakdown by sunlight has two root causes The first is the gradual breakdown of the coating material The second is the slight chemical and physical change which takes place within the surface wood cells affected by the sunlight through the clear coating It is thought that this change in the wood cells contributes to the coating failure by promoting a physical separation of an already weakened coating from the ultraviolet altered wood surface We are often asked how long a coating will last over a wooden surface The answer is not simple because the life span of any coating depends on many factors We consider the following to be the most important 1 The number of hours of exposure to sunlight in a given climate Cloudy climates are less hostile than sunny climates A southern Florida location is far worse than one in Maine because on average the solar radiation in Florida is less filtered by the atmosphere 49 Protecting and Maintaining Wooden Boats 230 e 220 Ky g9 o dv 210 q S oy 200 wy wv 190 i AVY T 180 E 170 y S KS phd NV S 160 KO E Y 2 150 AD eS amp 140 5 B 130 iy 120 110 100 90 80 70 30 40 50 60 70 80 90 100 Ambient Air Temperature F
64. einforcing members can be wood or metal At cockpit or cabin openings a carlin ties the ends of the short or half beams to a full beam at each end of the opening Extra knees and tie rods help to stiffen the sheer and transfer the load to the next full length beam In a small open boat the sheer must be stiff enough to resist flexing without the aid of deck beams In a canoe for example one or two thwarts replace a deck and the sheer must be stiff enough to resist flexing between the thwarts 2 1 2 The skin Inspecting and Evaluating 10 One of two basic types of skins covers the hull and deck structure providing a watertight membrane Variations of planking provided the only alternatives for covering wooden structures for thousands of years until modern adhesives made the plywood skin more common and more durable Planking Cotton Caulk Deck Planks Planking whether carvel or lapstrake or a variation of these is more susceptible to flexing and leaks than plywood The individual planks run generally parallel to the centerline of the boat Figure 2 2 They rely on fasteners at each framing member and the caulking to resist shear movement the slight sliding movement between planks when a hull twists In lapstrake planking where each plank overlaps the preceding one clinch fasteners or screws along the lap serve to tighten the lap and resist shear along the lap Joints between carvel planks were traditionally sealed with cotton a
65. els can pose special problems Deadwood can be inside or outside the planking line and typically has a fair number of exposed seams It is generally not wise to encase the skeg or deadwood ina fiberglass epoxy skin unless you have stabilized the joints in the structure Worm damage may require replacement of the specific pieces If work is needed on the garboards floors or frame heels it is a good idea to examine the keel while the garboards are off The joints and rabbets are prime locations for rot to start These joints between the pieces of the deadwood or skegs are notorious places for leaks The keel bolts or drifts passing from the ballast keel up through the deadwood keel and floors allow water to pass up and into the hull Follow these procedures to repair the keel 1 Remove the paint or any other coatings or coverings and allow the hull to dry out thoroughly possibly schedule this work for the spring after the boat has had the winter to dry out 2 When the seams are open or the keel or deadwood timbers have shrunken clean out any old paint caulking or debris Make sure that the wood in the joints is dry 3 Work epoxy thickened with 406 filler into the joints with a plastic spreader from one side until the epoxy comes out the other side Clean up excess epoxy from the surface and allow the epoxy to cure 4 Either coat the exterior of the skeg or deadwood with epoxy or cover it with a fiberglass epoxy skin 4 7 1 Keel bo
66. ened seams Use a plastic spreader to force the thickened epoxy into the seam as far as possible Figure 5 9 Check inside for epoxy leaking through the planks Clean excess epoxy before it cures Shape the thickened epoxy at the inside corner of the seam to a square inside corner or a cove shaped fillet A fillet increases the bonding area around the seam and provides more protection to the edge of each plank For more details on fillets see Section 8 4 3 Sand the seams and plank surfaces fair after the epoxy has cured thoroughly Fill and fair any remaining voids with an epoxy low density mixture Follow the coating finishing procedures in Section 7 5 3 Plywood hulls and decks Plywood has a high strength to weight ratio and makes an excellent boat building and repair material Douglas Fir is the most common wood species used in plywood Exterior construction grade plywood available at lumberyards has been used for boat building and repairs but if the boat is going to see offshore service we recommend a higher grade of plywood Medium Density Overlay MDO is used by some boatbuilders because the resin impregnated paper face provides a smooth base for paint and epoxy AA marine grade is the highest quality Douglas Fir plywood for marine repairs Mahogany plywood is the highest quality and first choice if the high costs are acceptable Repairing Hull and Deck Planking 34 Use a syringe to fill all voids found in lesser grades
67. epoxy 403 mayonnaise consistency Note 403 filler will leave an off white colored seam which will not matter if you plan to paint the surface If you plana clear finish you may want to use 405 Filleting Blend or a coloring agent mixed with the epoxy to match the planking color See Section 7 for information on finishing Large syringes or caulking tubes are convenient to inject the thickened epoxy into the seams Smooth the mixture flush with the surface and remove excess epoxy before it cures Check the inside for leaks and clean any excess epoxy before it cures Sand the surface fair after the epoxy cures thoroughly Fill any remaining low areas with epoxy low density filler mixture Coat the exterior following the procedures in Section 7 5 1 4 Repairing damaged planks in place If you will be repairing or replacing a lot of planks it is best to repair individual planks and small areas completely before going on to other areas The hull may be seriously weakened and lose its shape if you remove too many planks at one time Scarf joints or butt joints can be used in repairing damaged sections of planks without removing the entire plank Support the hull in its proper shape before bonding Scarf joint method To repair damaged sections of planks using scarf joints 1 Remove the damaged part of the plank using a circular saw hand saw or chisel 2 Bevel each end of the plank opening with an 8 to 1 scarf 3 Cuta piece of wood to
68. er Strength gap filling Bonding with Fillets lncrease joint bond ing area and create a structural brace be tween parts Smoothness strength Laminating Bond layers of wood strips ve neers planks sheets and cores Gap fill ing strength Fairing Fill low areas and voids with an eas ily shaped and sanded surface filler fairing compound Sandability gap filling Figure 8 2 Selecting Fillers As a rule use higher density fillers when bonding higher density materials such as hardwoods and met als Any of the adhesive fillers are suitable for most bonding situations Your choice of a filler for general use may be based on the han dling characteristics you prefer Fillers may also be blended to create mixtures with intermediate characteristics 59 Using WEST SYSTEM Epoxy 8 3 Handling epoxy This section explains the fundamentals of epoxy curing and the steps for proper dis pensing mixing and adding fillers to assure that every batch of epoxy cures to a useful high strength solid 8 3 1 Understanding epoxy s cure stages Mixing epoxy resin and hardener begins a chemical reaction that transforms the com bined liquid ingredients to a solid The time it takes for this transformation is the cure time As it cures the epoxy passes from the liquid state through a gel state before it reaches a solid state Figure 8 3 Figure 8 3 As it cures mixed ep oxy passes from a liquid state through
69. er woods like white oak Use full length strips Make the strips longer than the finished frame to allow for trimming The new frame width should be the same as the original frame Strips can be wider to allow for trimming and finishing after the frame is laid up Select wood strips that are seasoned Ideal moisture content is 6 to 14 4 1 1 Laminating in a jig A laminating jig will allow you to laminate a new frame in the controlled environment of your shop Use cardboard or other convenient material to pattern the top or bottom line of the damaged frame Transfer the pattern line to a laminating jig of one the types illustrated Figure 4 1 Laminate frames in a jig as follows Prepare the jig and the strips as suggested Go through a dry run to be sure the strips bend enough and that your jig and clamps can handle the bending of all of the strips Cover the jig with plastic to prevent the frame from bonding to the jig Wet out the strips on both sides with epoxy except for the outer faces of the top and bottom strip Transfer frame profile to cardboard Transfer profile to jig Figure 4 1 Transfer the desired frame shape to the jig 3 Apply thickened epoxy to one side of each strip and stack it in place on the jig against the previously coated strip Thicken the mixture with 406 filler to a catsup consistency Be sure one side coated with thickened epoxy faces each joint Clamp the strips to t
70. es Figure 8 5 To assure thorough mixing scrape the sides and bottom of the pot as you mix Use the flat end of the mixing stick to reach the inside corner of the pot If you are using a power mixer occasionally scrape the sides and corners of the mixing pot while mixing If you are going to be using the mixture for coating quickly pour it into a roller pan to extend the open time WARNING Curing epoxy generates heat Do not fill or cast layers of epoxy thicker than 2 thinner if enclosed by foam or other insulated material Several inches of mixed epoxy ina plastic mixing cup will generate enough heat to melt the cup if left to stand for its full pot life For this reason do not use foam or glass mixing containers Ifa pot of mixed epoxy begins to exotherm heat up quickly move it outdoors Avoid breathing the fumes Do not dispose of the mixture until the reaction is complete and has cooled 8 3 4 Adding fillers and additives Fillers After selecting an appropriate filler for your job Section 8 2 2 use it to thicken the ep oxy mixture to the desired consistency The thickness of a mixture required for a par ticular job is controlled by the amount of filler added There is no strict formula or measuring involved use your eye to judge what consistency will work best Figure 8 6 gives you a general guide to the differences between unthickened epoxy and the three consistencies referred to in this manual Figure 8 6 Epoxy can be
71. faces with lacquer thinner acetone or other appropriate solvent Wipe the surface with paper towels before the solvent dries Clean surfaces be fore sanding to avoid sanding the contaminant into the surface Follow all safety pre cautions when working with solvents All bonding surfaces must be as dry as possible for good adhesion If necessary acceler ate drying by warming the bonding surface with hot air guns hair dryers or heat lamps Use fans to move the air in confined or enclosed spaces Watch for condensation when working outdoors or whenever the temperature of the work environment changes 3 Sanded Sand smooth non porous surfaces thoroughly abrade the surface For most surfaces 80 grit aluminum oxide paper will provide a good texture for the epoxy to key into Be sure the surface to be bonded is solid Remove any flaking chalking blistering or old coating before sanding Remove all dust after sanding Special preparation for various materials Cured epoxy Amine blush can appear as a wax like film on cured epoxy surfaces It is a byproduct of the curing process and may be more noticeable in cool moist condi tions Amine blush can clog sandpaper and inhibit subsequent bonding but it can easily be removed It s a good idea to assume it has formed on any cured epoxy surface To remove the blush wash the surface with clean water not solvent and an abrasive pad such as Scotch brite 7447 General Purpose Hand Pads
72. force epoxy to the sides making good contact with the spline and edges of the planks The spline should fit snugly in the seam with hand pressure after a small amount of epoxy squeezes out of the joint Staple the spline if necessary to hold it in position Clean up excess epoxy Use a sharpened mixing stick to scrape up excess epoxy before it cures Station a helper inside the boat or check the inside frequently to clean any epoxy leaking through the planking After the epoxy cures thoroughly remove the excess portion of the spline with a plane followed by coarse sandpaper Figure 5 5 Fill the vertical seams and any remaining voids with epoxy 407 fairing compound before final fairing and finishing Important Coat the exterior following the procedures in Section 7 Failure to apply an epoxy moisture barrier may cause structural damage when planks swell Fiberglass cloth is often applied to provide additional reinforcing and abrasion resistance 5 1 3 Filling the seams with epoxy A quicker but more expensive way of bonding the seams is to fill the entire gap with thickened epoxy epoxy is more expensive than wood by volume This method is more practical on seams that are too curved or tight for a spline Open the seam as before The gaps do not have to be a particular width as long as you expose fresh wood on each plank edge 2 Wet out the gap with resin hardener mixture 4 5 Fill the seam with thickened
73. frames or doublers Sister frames are bonded alongside a damaged frame to restore the strength of the original frame This method may not look as good as a replaced frame but it will save time especially if the damaged frame is difficult to remove Install sister frames as follows Laminate a full sister frame slightly longer than the existing frame and trim it to fit tight against the damaged frame Laminate a partial sister frame so that it will extend past each end of the damaged area twelve times the thickness of the frame Frame 4 6 A sister frame may also be carved out of solid wood Use the same wood as the existing frame Sister Frame Figure 4 6 Laminate a partial sister frame longer than the dam aged area Prepare the contact areas of both frames and the skin for bonding Avoid bonding to the planking or plywood if it will later be removed Install the new frame section Wet out all contact surfaces of the new and existing frames Apply a liberal amount of thickened epoxy 406 mixture to one side of each contact area Clamp the section in position Clean up excess epoxy before it begins to cure Remove clamps after epoxy cures thoroughly Repairing the Structural Framework 22 4 5 Joint repairs If the framing is not damaged from rot or impact you may still want to bond the framing together to stiffen the structure and seal the joints against moisture Remove as many frames as you can and bond them in
74. fter applying epoxy with 800 Roller Cover force epoxy into pinholes with a stiff plastic or metal spreader held at a low nearly flat angle Recoat and tip off coating after all pinholes are filled 1 Coat the wood as its temperature is dropping af ter warming the wood with heaters or during the later part of the day 2 Apply a thinner coat allowing air to escape eas ier 3 Tip off the coating with a roller cover brush to break bubbles 75 Wood data Wood data Percentage increase in wood strength properties for 1 decrease in moisture content Compression parallel to Static bendin grain Shearing Fiber stress Modulus Modulus Work to maximum Compression strength at propor of of maximum crushing perpendicular parallel Side Species tional limit rupture elasticity load strength to grain to grain hardness Ash white 4 1 3 5 1 4 0 4 4 7 48 2 9 2 4 Birch yellow 6 0 48 2 0 1 7 6 1 5 6 3 6 3 3 Cedar northern white 5 4 3 6 1 8 1 5 5 9 2 3 2 8 3 0 Cedar Port Orford 5 7 5 2 1 6 17 6 2 6 7 2 2 2 8 Cedar western red 43 3 4 1 6 13 5 1 6 1 1 6 i 23 Fir Douglas 45 3 7 1 8 1 9 5 5 5 0 1 7 2 9 Hickory true 49 48 2 8 0 7 5 9 6 6 3 9 Mahogany Honduras 2 6 1 3 0 8 2 9 25 39 aes 1 0 Pine eastern white 5 6 4 8 2 0 2 1 a7 5 6 22 22 Spruce Sitka 4 7 3 9 T7 2 0 5 3 4 3 26 24 1 Extracted from Munitions Board Aircraft Committee Design of Wood Aircraft Structures ANC 18 1951 National Technical Information
75. g mixed resin and hardener without fillers added and thickened mixture or thickened epoxy meaning resin hardener with one of six fillers added Fillers are used to thicken the epoxy for specific applications They are categorized as either Adhesive Fillers used for structural bonding or gluing and gap filling or Fair ing Fillers used for cosmetic surface filling Although each filler has unique handling and cured characteristics that make it more suitable for some jobs than others Figure 8 2 for most bonding applications any of the adhesive fillers can be used And for most surface filling either of the fairing fillers can be used Fillers may also be blended for intermediate characteristics Using WEST SYSTEM Epoxy 58 Adhesive fillers 403 Microfibers For general bonding and gap filling Epoxy 403 mixtures have su perior gap filling qualities and good strength for most bonding applications while re taining wetting penetrating capabilities Works especially well with porous woods Cures to an off white color 404 High Density Filler For hardware fastener bonding and applications that re quire maximum physical properties and where high cyclic loads are anticipated Also used for gap filling where maximum strength is necessary Cures to an off white color 405 Filleting Blend For use in bonding and filleting on naturally finished wood pro jects A strong wood toned filler that mixes easily and spreads smoothly Cures to a
76. g a joint Failing to coat the inaccessible contact surfaces of joints can create ideal environments for dry rot if there is a leak So keeping the interior well ventilated is often a better solution than attempting to coat areas that may trap moisture The object is always to deny at least one of the four conditions necessary for rot to survive in this case keeping the wood moisture content below the saturation point If you can t guarantee keeping water out of the structure the next best option is to guarantee that it is not trapped in What about coating the exterior of the hull If you eliminate movement between the hull planks by bonding them together coating the exterior of the hull is a good idea When the framing is sound edge bonding the planking coating the exterior and ventilating the interior is a good intermediate repair It adds a lot of stiffness to the structure eliminates a source of moisture entering the boat and when the boat is properly ventilated does not trap moisture in the boat 1 4 3 Ventilating for longevity Ventilation is the key to the continued longevity of your boat No boat is maintenance free Either you consider preventive maintenance or you accept periodic rebuilding and repair All boats wood fiberglass aluminum and steel need good ventilation Keeping the boat s interior as dry as possible is the best preventive maintenance for preserving the structure and making the boat more comfortable Clean
77. h acetone or lacquer thinner 30 minutes before bonding Wet out the mating surface of the first few pieces of teak and the deck in the area of the first few strips with unthickened resin hardener Apply a thickened epoxy mixture over the wet out deck surface Use 404 High density filler thickened to catsup mayonnaise consistency depending on deck fairness and add just enough 423 Graphite Powder to turn the mixture to an opaque black color Apply a layer just thick enough to span any gaps and to squeeze up between the planks An 809 Notched Spreader works well to apply an even layer over the substrate Locate your reference points and set the first strips in place Repairing Hull and Deck Planking 42 6 Clamp the plank in place with 10 sheet metal screws and large washers Place the screws and washers between the strips 8 apart Each row of screws will clamp the edges of two adjoining planks and act as spacers Figure 5 24 left Coat the screws and washers with a mold release or place a small sheet of plastic under the washers to prevent bonding Washers may also be cut from stiff plastic thin wood lathe or similar stock with holes drilled for the screws Tighten the screws down completely after pushing both adjoining strips tight against the screws The epoxy mixture should squeeze up between the strips Any voids between the planks should be filled at this time with the epoxy 404 graphite mixture _ 10 Sheetmetal Fill holes
78. h scarfs Staple through the veneers into the stringers and at the scarfs as necessary to hold the veneers flat Continue until all the veneers are in place and you ve matched the thickness of the original skin Figure 5 19 By removing the staples in the previous layer only under the new veneer all previous layers of veneer will stay in place even though the epoxy has not thoroughly cured This will allow you to bond several layers of veneers in one continuous operation Be sure the staples are long enough to provide clamping pressure by penetrating to the stringers or veneers that have cured fully Allow the final layer to cure thoroughly before removing staples fairing and final finishing 5 4 2 Laminating a patch away from the damaged area A panel section also can be repaired by using the existing skin as a form to laminate a patch panel and then bonding the pre formed patch in in one piece The size of the patch should include the damaged area plus an 8 to 1 scarf beyond the damaged area Tape a sheet of plastic over and beyond the area you wish to use as a mold surface An adjacent area that is curved slightly more than the damaged area is an ideal mold surface because it compensates for veneer springback during molding Figure 5 20 After laminating the appropriate number of veneers to equal the size and thickness of the damaged section plus scarf prepare matching scarfs on the damaged area and the patch Then bond the patch into p
79. he jig until the epoxy cures Figure 4 2 Use clamps wedges staples or small nails to apply enough pressure to squeeze a small amount of epoxy from each joint 19 Repairing the Structural Framework Epoxy should squeeze from the wee Use plastic to avoid bonding to jig clamps or work surface B Figure 4 2 Clamp the appropriate number of coated strips into the jig Trim the frame to size after the epoxy is fully cured Remove the frame from the jig after the epoxy has thoroughly cured Be sure to allow extra cure time if the temperature is cool especially if you expect a lot of springback Trim the frame to its final shape and finish as desired 4 1 2 Laminating frames in place A B The new frame or frame section can in some cases be laminated directly in place in the hull The existing structure can be used as the laminating jig in one of the following ways Bond all of the strips permanently to the structure in one continuous operation either one ata time or all at the same time depending on the best available clamping method Use non corroding screws or staples to bond strips in place one at a time if temporary clamping is not feasible Try a dry run to see which method will work best Trim all of the strips to size before bonding Bond all of the strips together in place with plastic over the hull contact area to prevent immediate bonding to the hull Remove the laid up frame and trim to
80. hesion varies If a plastic is impervious to solvents such as acetone epoxy generally will not bond to it Soft flexible plastics such as polyethylene polypropy lene nylon Plexiglas and polycarbonate fall into this category Hard rigid plastics such as PVC ABS and styrene provide better adhesion with good surface preparation and adequate bonding area After sanding flame oxidizing by quickly passing propane torch over the surface without melting the plastic can im prove bonding in some plastics Its a good idea to conduct an adhesion test on a plastic that you are uncertain about 8 4 2 Bonding gluing EA Wet out To Precoat a joint s bonding surfaces with unthickened epoxy for maximum pene tration and adhesion be fore an additional coat of thickened epoxy is applied Especially useful and rec ommended on porous sur faces This section refers to two types of structural bonding Two step bonding is the preferred method for most situations because it promotes maximum epoxy penetration into the bonding surface and prevents resin starved joints Single step bonding can be used when joints have minimal loads and excess absorption into porous surfaces is not a problem In both cases epoxy bonds best when it is worked into the surface with a roller or brush NOTE Joint strength the ability to adequately transfer a load from one part to another depends on the combined effects of three factors GLUE STRENGTH Careful
81. ies have low VOC content but vapors can build up in unvented spaces Provide ample ventila tion when working with epoxy in confined spaces such as boat interiors When ade quate ventilation is not possible wear a NIOSH National Institute for Occupational 8 1 1 Cleanup Y Using WEST SYSTEM Epoxy 56 Safety and Health approved respirator with an organic vapor cartridge Provide venti lation and wear a dust mask when sanding epoxy especially uncured epoxy Breathing uncured epoxy dust increases your risk of sensitization Although epoxy cures quickly to asandable solid it may take over two weeks at room temperature or post curing to cure completely Avoid ingestion Wash thoroughly after handling epoxy especially before eating or smoking If epoxy is swallowed drink large quantities of water DO NOT induce vomiting Because hardeners are corrosive they can cause additional harm if vomited Call a physician immediately Refer to First Aid procedures on the Material Safety Data Sheet KEEP RESINS HARDENERS FILLERS AND SOLVENTS OUT OF THE REACH OF CHILDREN For additional safety information or data write to EPOXY SAFETY Gougeon Broth ers Inc PO Box 908 Bay City MI 48707 USA or visit www westsystem com Contain large spills with sand clay or other inert absorbent material Use a scraper to contain small spills and collect as much material as possible Follow up with absorbent towels Uncontaminated resin or h
82. intaining Wooden Boats 50 Figure 7 2 UV test samples after 3600 hours in weathering machine types surface preparations and coating substrates in a controlled test environment Figure 7 2 This testing has allowed us to evaluate a wide range of variables and samples and has guided us in the development of WEST SYSTEM 207 Special Coating Hardener When used with a high quality two part polyurethane they provide a superior quality clear finish with excellent resistance to damage from moisture and UV radiation 7 2 Applying the final epoxy coatings The object of final coating is to build up an epoxy coating that provides and effective moisture barrier and a smooth base for clear coatings or paint A minimum of two coats of WEST SYSTEM epoxy will provide an effective moisture barrier Apply three coats when sanding is required Since sanding is required before applying the finish coating this is the standard practice Apply up to five or six coats if you plan to do a lot of sanding or want the maximum moisture barrier or a deeper finish Each coat achieves a 3 4 mil thickness The maximum recommended thickness is 15 20 mil We recommend WEST SYSTEM 207 Special Coating Hardener be used for the highest quality longest lasting clear finish 207 contains a UV filter that improves the ability of the mixed 105 207 epoxy to resist the harmful effects of sunlight without compromising moisture resistance Keep in mind that although 207 is very clear
83. ints in general is not recommended except if done by a trained professional with industrial grade equipment and only in properly ventilated areas We are often asked how many coats of varnish you should apply The answer is the more the better with the important understanding that the final coat always needs a high gloss for longevity Initially apply one or two coats over the 105 207 epoxy base Then plan to apply a new coat every year or two to assure a continued glossy surface This approach not only renews the surface to a high gloss but also takes care of any dings or scratches Thus it has the potential to provide the longest lasting finish before you have to strip the surface back to bare wood and refinish from scratch The longest lasting finishes are fully pigmented paints Pigments filter out all or most of the harmful UV rays thus protecting the substrate However a slow oxidation of the surface occurs over many years causing it to lose its gloss Light colored paints are more reflective and maintain their gloss longer than darker colors Protecting the substrate from heat is another important reason to choose lighter colors Figure 7 1 We have tried many types of paint supplied by a variety of manufacturers The more recently developed linear polyurethanes LP are superior to any other paint we have used We recommend them as the best painting system to use over a cured WEST SYSTEM epoxy surface The LP systems have excellent resist
84. ints with Thiokol or polysulfide caulk Figure 5 24 right 43 Installing Hardware 6 Installing Hardware Now that the deck is upgraded the hardware should receive the same thorough attention To overcome problems associated with hardware installation on wooden boats Gougeon Brothers Inc has developed an approach called hardware bonding As the name implies hardware items are bonded glued to wood with the goal of distributing high single point loads over as large an area of wood fiber as possible while allowing the epoxy to seal and protect the wood end grain exposed by the fastener hole Note the term hardware bonding as used in this manual does not refer to the electrical bonding of hardware to eliminate stray current corrosion There are two ways to do this The first is to bond all fasteners screws bolts or threaded rod directly to the surrounding wood fiber The second is to bond both the fasteners and the hardware itself to the immediate wood fiber on which it rests Using proper hardware bonding installation techniques you can dramatically improve the load carrying capacity of your hardware over that possible with standard hardware installation methods In saltwater applications our experience has been that bonded hardware and fasteners show excellent resistance to corrosion attack Where fasteners are vulnerable to flexure and saltwater attack e g hollow or bridged traveler tracks bonded U bolts or solitary eyeb
85. ir definition 2 Resin 56 Resin starved joints 66 Restoration definition 2 S Safety 55 Scarf joint method 30 Seams carvel plank 28 Shelf life epoxy 72 Single step bonding 66 Sister frames installing 21 Stiffness loss of 4 Structural framework repairing 17 Structural framework understanding 8 Stud bonding 46 Sunlight effects of 48 Surface preparation 63 T Teak veneer deck installing 41 Teak bonding to 64 Thinning epoxy 16 Threaded rods bonding 46 Two step bonding 65 66 U Ultraviolet degradation 48 protection 50 Using the manual 2 V Vacuum bagging for laminating 67 Ventilating for longevity 7 Ventilation 54 Ww WEST SYSTEM epoxy suitability for repair 5 Wet out 65 Wooden boats why they fail 4 Additional building and repair information available from Gougeon Brothers Inc Publications Video 002 970 Sg GOUGEON 002 950 WEST SYSTEMe User Manual amp Product Guide The primary guide to safety handling and the basic techniques of epoxy use In cludes a complete description of WEST SYSTEM epoxy resin hardeners fillers additives reinforcing materials tools supplies and publications 002 The Gougeon Brothers on Boat Construction This book is a must for anyone building a boat or working with wood and WEST SYSTEM epoxy Includes extensive chapters on composite construction tech niques materials lofting safety and tools with many illustrations
86. ister Repair with WEST SYSTEM Brand Epoxy A guide for repairing and preventing gelcoat blisters on fiberglass boats In cludes an analysis of the factors contributing to blister formation and steps for preparation drying repairing and coating for moisture protection VHS 16 min Wooden Boat Restoration amp Repair Published by Gougeon Brothers Inc PO Box 908 Bay City MI 48707 989 684 7286 Fax 989 684 1374 www westsystem com WEST 6th Edition Printed 04 03 SYSTEMA BRAND
87. it is not colorless It has a light amber color similar to spar varnish that will tint wood slightly warmer and darker If you are not interested in a clear finish select the hardener 205 206 or 209 that best meets your needs General procedures for final epoxy coating are listed in the WEST SYSTEM User Manual c amp Product Guide The following are specially applicable for using 207 Special Coating Hardener to prepare for a deep lustrous finish in the fastest possible time 1 Sand and fair the wood surface using 80 grit or finer paper Always sand in the grain direction 2 Apply a saturation coat of 105 207 to the bare wood surface and allow to cure thoroughly at room temperature The cured saturation coat will cause the wood surface to swell up and feel rough Wash and sand or scrape the swelled wood grain to a moderate smoothness Be careful to avoid sanding through this initial saturation coat 51 Protecting and Maintaining Wooden Boats Figure 7 3 Roll lightly and randomly over a small Figure 7 4 Tip off the coating by dragging a foam area Spread the epoxy into a thin even film roller brush lightly over the fresh epoxy 3 Apply asecond coat of 105 207 using the roller Figure 7 3 and tip off the surface with a foam brush Drag the brush across the surface of the fresh epoxy in light overlapping strokes in the direction of the wood grain Figure 7 4 Level out the coating as muchas possible NOTE Apply the epoxy in
88. ixture so there are no voids in the hole after inserting the fastener Coat the bottom of the hardware and the fastener threads with the thickened mixture 7 Place the hardware in position Insert and tighten fasteners until a small amount of the mixture squeezes out of the joint Figure 6 2 Do not over tighten 8 Clean the excess epoxy mixture that has squeezed out 9 Allow the epoxy to cure at least 24 hours before applying load to the hardware Allow more time in cool weather Bonding the contact surface of a hardware item can contribute a great deal to load distribution over maximum wood surface area You can use WEST SYSTEM epoxy to make good bonds with most metals However careful preparation of the metal surface is necessary for good adhesion This includes sanding and acid etching For example aluminum requires a two step surface preparation The first step involves the use of an acid conditioner that removes corrosion The second step chemically stabilizes the surface and prevents oxidation allowing time for coating or bonding The WEST SYSTEM 860 Aluminum Etch Kit contains complete instructions 45 Installing Hardware 6 3 Casting epoxy bases for hardware Occasionally fittings must be set at specific angles to the hull or deck surfaces Downrigger bases lifeline stanchions winches and turning blocks are all good examples Traditionally hand carved wedge shaped shims have been used to achieve the proper angles with s
89. lace using the procedure described previously in Section 5 3 2 Figure 5 20 Laminate a replacement panel using the surface next to the damaged area as a mold 5 4 3 Laminating a new skin over an old skin The technique of laminating one or more veneers over an existing hull has breathed new life into many boats that otherwise would have been given up for dead The thickness and species of the new skin depends on how much strength is left in the old skin If the hull can be supported in the proper shape the new skin could replace the function of the old skin entirely After you ve established the total thickness and type of wood determine the thickness and number of layers of veneer As a rule use the thickest and fewest layers of veneers that can bend and clamp to the tightest curves on Repairing Hull and Deck Planking 40 the hull Bonding all the seams of a planked hull before adding veneers to the hull will add stiffness and reduce the total thickness of veneers required see Section 5 1 Laminate veneers to an existing skin as follows Prepare the existing hull for bonding Be sure the surface is clean dry and sanded Support the hull in its proper shape Fill and fair low areas that are too big for the veneers to bridge Grind off any high spots that could keep the veneers from lying flat Bond the first veneer about midpoint on the hull Use the one step bonding technique Section 8 4 2 with an epoxy 403 filler mixture
90. lanning an overall restoration of the boat the comprehensive use of epoxy as the adhesive and moisture coating will give you a very stiff and durable structure What if you are not planning a total rebuild but are interested in large or small local repairs to a basically sound boat Bonding and encapsulating wood with epoxy can greatly increase the local or the overall stiffness of a boat Most of the time this stiffness if beneficial Occasionally if the job is not well planned the newly introduced stiffness can have a detrimental effect usually in the form of stress concentration on the durability of the repairs or the integrity of the original boat First identify the structural unit that you want to repair and how it fits in the overall boat structure Look for structural units where the newly introduced stiffness will not work against the original structure Many times this approach can help you set limits to the repair job We suggest that you look for the logical breakdowns in the structure Scarfing a plank rebuilding a hatch replacing the transom replacing a frame rebuilding the top of a deck house replacing all of the deck all of these are possibilities Edge bonding the hull planking with epoxy after cleaning the seams is the single best thing you can do 1 4 2 Coating for moisture protection Encapsulating offers a valuable advantage to new wooden boats by forming a continuous moisture barrier over every part of the boat in
91. layout so that scarf joints will fall over beams for better clamping 37 Repairing Hull and Deck Planking 5 Clamp the sheet temporarily with drywall screws or staples Use enough fasteners to clamp the sheet evenly The epoxy mixture should squeeze out of the joints assuring good adhesive contact Station someone inside to clean excess epoxy at the frames and joints The excess can be scraped clean or shaped into a fillet before it begins to cure Repeat the process with the remaining sheets Allow the joints to cure thoroughly before removing temporary fasteners Sand the joints and fair the surface before adding another layer of plywood fiberglassing Section 8 4 5 or finishing Section 7 5 3 4 Applying plywood over existing skins When laminating an additional layer of plywood over an existing hull or deck it s not necessary to scarf joints or place joints directly over frames because of the large bonding area Restore existing plywood to sound condition before laminating new sheets over it Laminate new plywood over an existing deck or hull as follows Rebond delaminated layers of plywood after drying thoroughly Drill a pattern of 1 8 holes in the delaminated area Use a syringe to inject a slightly thickened epoxy 406 mixture in all of the holes to reach all of the delaminated area Use staples or screws to clamp the layers together until the epoxy cures When the epoxy has cured thoroughly proceed with Step 2
92. lt repair If there has been leaking around the keel bolts floor bolts rudder tube or propeller shaft follow these procedures 1 Support and secure the boat and ballast keel 2 Fabricate a deep engagement hole saw by first cutting the end off a hole saw of slightly larger diameter than the bolt to be repaired Braze the hole saw teeth to the end of a pipe of the same diameter and long enough to chase the length of your longest keel bolt Weld a piece of round stock into the other end of the pipe to serve as a bit for a drill chuck If you have many bolts of many lengths to do you may want to make several hole saws of different lengths Figure 4 13 Repairing the Structural Framework 26 Threaded Rod Steel Conduit Cut Off Hole Saw Grind threads to form a smooth shank Plasticine Dam Weld and grind smooth Allow epoxy to penetrate endgrain around bolts Figure 4 13 A custom keel bolt saw can be made from a pipe Figure 4 14 Build an epoxy reservoir around each keel bolt section and a standard hole saw 3 After removing the nuts washers or clinch rings use the hole saw to chase down along the bolt The typical hole saw will produce a clean 0 125 annulus around the bolt Be sure the wood is completely dry 4 After blowing out the dust and shavings wrap duct tape around the bolt threads and construct a 1 4 high dam around the bolt hole with plasticine modeling clay Figure 4 14 5 Overfill the h
93. manently tied together with epoxy and threaded rods With this completed bond the planking removed earlier to the keel and frames 1 Prepare the planking and frames for bonding Remove all old paint or varnish Sand 4 the areas to be bonded to expose new wood fiber 2 Dry fit the planks to the hull Drill new holes for screws if the old ones don t align Be sure you have enough clamps to draw the planks to the frames New Floor and a Figure 4 12 Bond the garboard back into position next to the keel 25 Repairing the Structural Framework 3 Wet out the screw holes new and old in the planks frames and keel with resin hardener mixture using a pipe cleaner or syringe Wet out the edges and inside surface of the plank and the bonding areas of the keel and frames with resin hardener mixture 4 Apply liberal amounts of thickened epoxy 406 filler to the mating surfaces of the keel and frames 5 Install the garboard with the original screws Figure 4 12 Start at the middle and work toward both ends 6 Form a fillet along the keel garboard joint with the excess epoxy and form a fillet where the planking meets the frames 7 Follow the same procedure and install the garboard on the opposite side of the keel 8 Bond the remaining planks together following procedures discussed in Section 5 4 7 Keel repair A keel is a major structural component and should get extra care and special investigation Skegs deadwood or fin ke
94. metering and thorough mixing will assure the epoxy mixture cures to full strength SURFACE PREPARATION For the best adhesion and load transfer the surface must be properly prepared JOINT AREA The bonding area or adhesive area of the joint must be adequate for the load on the joint Increased overlap scarf joints fillets and reinforcing fibers across the joint can be used to increase bonding area Before mixing epoxy check all parts to be bonded for proper fit and surface prepara tion Surface preparation 8 4 1 gather all the clamps and tools necessary for the op eration and cover any areas that need protection from spills Two step bonding 1 Wet out bonding surfaces Apply a neat resin hardener mixture without fillers to the surfaces to be joined Figure 8 8 Wet out small or tight areas with a disposable brush Wet out larger areas with a foam roller or by spreading the resin hardener mix ture evenly over the surface with a plastic spreader You may proceed with step two im mediately or any time before the wet out coat becomes tack free Figure 8 8 Wet out the bonding surfaces by applying Figure 8 9 Apply thickened epoxy to one of the bond resin hardener mixture with a brush or roller ing surfaces Using WEST SYSTEM Epoxy 66 2 Apply thickened epoxy to one bonding surface Modify the resin hardener mixture by stirring in the appropriate filler until it becomes thick enough to bridge any gaps between the mating
95. mixed epoxy in a liquid state over 120 F 49 C 61 Using WEST SYSTEM Epoxy Regardless of what steps are taken to control the cure time thorough planning of the application and assembly will allow you to make maximum use of the epoxy mixture s open time and cure time 8 3 3 Dispensing and mixing Careful measuring of epoxy resin and hardener and thorough mixing are essential for a proper cure Whether the resin hardener mixture is applied as a coating or modified with fillers or additives observing the following procedures will assure a controlled and thorough chemical transition to a high strength epoxy solid Dispense the proper proportions of resin and hardener into a clean plastic metal or wax free paper container Don t use glass or foam containers because of the potential danger from exothermic heat buildup DO NOT attempt to alter the cure time by alter ing the ratio An accurate ratio is essential for a proper cure and full development of physical properties Dispensing with Mini pumps 1 stroke 1 stroke Resin Hardener Most problems related to curing of the epoxy can be traced to the wrong ratio of resin and hardener To simplify metering we recommend using calibrated WEST SYSTEM Mini Pumps to dispense the resin and hardener 301 Mini Pumps and 303 Special Ra tio Mini Pumps are calibrated to deliver the proper working ratio of resin to hardener Pump one full pump stroke of resin for each one full pump str
96. nd or oakum caulking driven into the seams with a caulking iron and filled over with tar or flexible sealant Driving the caulking into the seams helped to stiffen the boat initially but caulking needed to be redone as the boat s fasteners worked and the planking swelled or shrank Double planking was usually two layers of carvel or square seam planking sealed between seams and layers with shellac paint bedding compounds or glue Occasionally canvas bedded in paint or white lead would be used between the planking layers Figure 2 2 Typical laid plank deck and carvel planked hull Figure 2 3 Typical plywood construction Plywood Plywood often replaces the many individual planks greatly reducing the number of joints that are potential sources for leaks The framework for a plywood skin is similar to the framework for planking But because the plywood is strong in more than one direction the framework for plywood covered structures can be much lighter The extra frames required in a planked structure to resist diagonal movement can be eliminated The plywood sheets are usually glued to the framework and held in place with staples nails or wood screws Figure 2 3 Multiple layers of thinner plywood are used on surfaces with compound curves where a single thick layer can t bend enough in both directions Plywood can also suffer from moisture problems Moisture can penetrate plywood through the end grain at seams causing delaminati
97. nded to the substrate the epoxy still provides a bearing surface that perfectly matches and supports the base of the hardware Figure 6 4 Bond threaded rods or studs into the substrate as an alternative for easily removable hardware 1 Prepare the studs threaded rods by waxing the upper ends above the surface and cleaning the lower ends below the surface 2 Place a nut and washer on the studs wet out the lower ends and push them into the epoxy filled holes Allow the epoxy to cure thoroughly before tightening the nuts Figure 6 4 47 Installing Hardware 6 5 Removable hardware Testing at Gougeon Brothers Inc has shown that with bonded fasteners screws bolts threaded rods etc the adhesive bond to the metal is not as important as the keying between the epoxy and the threads of the fastener This factor allows the builder to coat the fastener with a thin film of mold release before bonding to permit easy fastener removal after the epoxy cures Fatigue tests of bonded threaded rods with and without a thin coating of mold release show only a 4 10 reduction in the overall fatigue strength of the fastener with mold release A thin film mold release will yield a more predictable performance than a thick film Mold release may include paste wax non stick cooking spray silicone spray or hair spray While the reduction in strength of the fastener treated with mold release is slight it should be taken into acc
98. need to decide the level of repair that suits you and your boat Theoretically no boat is beyond restoration realistically you need to evaluate thoroughly the soundness of the structure and the time and expense needed for repair If you have limited experience with rebuilding we advise hiring a surveyor before getting heavily involved 1 1 2 Determine your commitment Consider these factors when determining your commitment to repair or restore Time and resources Many people have become romantically involved with restoration projects and have failed to make their dreams a reality Others have started projects which required far greater financial and time commitments that they were able to allocate and have been forced to abandon the project You need to carefully assess the money and the time that you have available and can afford to commit Consider for example whether you can restore specific areas of your craft each year spreading the work and expense over time Do you have adequate space and equipment for the project Historical value If you have a very old boat that you are considering restoring investigate its background to see if it has historical or collector s value If you have an Adirondack guideboat an old wood and canvas canoe a Herreshoff a Rushton or some other historically significant boat wholesale repairs with epoxy may not be appropriate You owe it to yourself and the boat to do some research into the boat s v
99. ng Localized Dry Rot 3 2 Drilling and filling A common but much less effective method of dealing with rotted areas is to drill a pattern of holes in the affected area and inject epoxy into the holes to penetrate and stabilize the area This is a last resort method especially if wood strength is critical The biggest problem with this method is that you can never be sure of the extent of epoxy penetration into the damaged wood Testing of the physical properties of repaired samples shows drilling and filling to be inferior to excavating and filling Also drilling and filling is impossible on overhead surfaces and difficult on vertical surfaces However it may be useful in some situations where maximum strength is not required or the rotted area is too difficult to reach for excavating and filling If you choose this method we recommend the following procedure 1 Drill a pattern of diameter holes over the rotted area Space the holes 1 or less from center to center in all directions Drill each hole deep enough to pass through the rot just into solid wood On vertical surfaces drill the holes downward at approximately 45 2 Dry the area thoroughly If necessary use heat guns or fans to accelerate drying 3 Inject or pour resin hardener mixture into the holes Epoxy penetration can be improved by first warming the wood with a heat gun On contact with the warmed wood epoxy will become thinner and penetrate more deeply into the ex
100. ng the deck skin The end of each beam rests on and is connected to the sheer clamp and is usually connected to a frame end as well The sheer clamp is connected to both the beams and the frame ends It ties all the frame ends and beams together along the top of each side of the hull the sheer from stem to transom On larger boats a shelf attached to the sheer clamp on the flat helps to support the beams and stiffen the sheer The clamp sits vertically against the frame ends and the shelf lies horizontally under the end of the beam The shelf and sheer clamp are connected at approximately right angles Some round bottom boats may have intermediate bilge stringers providing additional stiffness along the turn of the bilge These stringers running fore and aft are located halfway between the keel and the sheer clamp On flat bottom multi chine or v bottom boats the intermediate fore and aft stringers are called chines or chine logs These structural members can be quite light in certain types of construction but can be very heavy equaling the size of keel or clamp in some traditional boats On powerboats and large sailboats the engine beds or stringers can be very large Typically they will run some distance fore and aft of the engine and be tied into the floors of special bulkheads On some larger boats there will be knees or strapping installed beneath the planking and decking to resist diagonal or torsional movement These additional r
101. o remove You may be able to replace only the damaged portion restoring the strength of the frame while leaving the frame in position in the boat 1 Cut out the damaged section of the existing frame Trim the exposed ends to a minimum 8 to 1 scarf angle Figure 4 4 The longer the scarf angle the stronger the joint When repairing hardwood or highly loaded frames use a longer 12 to 1 scarf angle Silicon Bronze fasteners if permanently left in Figure 4 4 Cut out all of the damaged area leaving at Figure 4 5 Bond in a new laminated or solid section trimmed to least an 8 to 1 bevel on the ends of the damaged frame fill the void in the existing frame 21 Repairing the Structural Framework 2 Laminate a new piece slightly larger than the removed section or carve a new section out of solid wood using the same wood as the existing frame Trim the new section to fit the size and shape of the void in the existing frame Cut a matching scarf angle on each end of the frame section Prepare the surfaces for bonding Trim the new piece and existing frame ends as necessary for a good fit Install the new frame section Figure 4 5 Wet out all contact surfaces of the new and existing frame ends Apply a liberal amount of thickened epoxy 406 mixture to one side of each contact area Clamp the section in position Clean up excess epoxy before it cures Remove clamps after epoxy cures thoroughly 4 4 Installing sister
102. oden Boats 48 7 Protecting and Maintaining Wooden Boats 7 1 Sunlight and protective coatings Sunlight poses a threat to the structure and finish of all composite boats It attacks in two ways heat and ultraviolet UV rays Any epoxy finishes without protective coatings are vulnerable to rapid ultraviolet degradation WEST SYSTEM Brand epoxy including the 207 Special Coating Hardener is not intended to be used as a final finish Therefore you should cover bare epoxy that will be exposed to direct sunlight as soon as possible with an opaque paint or a clear coating varnish If the surface is to be painted add pigment to the last two coats of epoxy to protect the surface Surfaces that receive indirect UV exposure such as those below decks will last much longer without a protective coating than directly exposed surfaces While a clear coating has an inherently shorter life span than a paint finish there is a tradition among wooden boat owners of using clear coatings to preserve and enhance the natural beauty of wood For many the major attraction of wooden boats is the beauty of wood itself and they are willing to invest a lot of time and money to achieve near perfection in their wood finishes Unfortunately these beautiful finishes seldom last forever because of exposure to the sun The boats must ultimately be stripped down and redone usually at great expense Because of this owners want the finish to have the longest possible lif
103. of curing epoxy the less it is affected by exothermic heat and the slower it cures Controlling cure time In warm conditions use a slower hardener if possible Mix smaller batches that can be used up quickly or quickly pour the epoxy mixture into a container with greater sur face area a roller pan for example thereby allowing exothermic heat to dissipate and extending open time The sooner the mixture is transferred or applied after thorough mixing the more of the mixture s useful open time will be available for coating lay up or assembly In cool conditions use a faster hardener or use supplemental heat to raise the epoxy temperature above the hardeners minimum recommended application temperature Use a hot air gun heat lamp or other heat source to warm the resin and hardener before mixing or after the epoxy is applied At room temperature supplemental heat is useful when a quicker cure is desired NOTE Unvented kerosene or propane heaters can in hibit the cure of epoxy and contaminate epoxy surfaces with unburned hydrocarbons w CAUTION Heating epoxy that has not gelled will lower its viscosity allowing the ep oxy to run or sag more easily on vertical surfaces In addition heating epoxy applied to a porous substrate soft wood or low density core material may cause the substrate to out gas and form bubbles in the epoxy coating To avoid outgassing wait until the epoxy coating has gelled before warming it Never heat
104. of plywood with thickened epoxy after cutting the panel to final shape Lesser grades of Douglas Fir plywood may require a layer of fiberglass cloth to prevent grain checking 5 3 1 Rebuilding a plywood joint If the seam between plywood sheets has deteriorated you can clean out the joint seal the edges with epoxy and reinforce the joint with fiberglass tape applied with epoxy The seam may be on a flat surface or at an edge or chine Rebuild a plywood joint as follows Clean out the seam by running a circular saw or scraping tool along the seam Set the depth of the saw cut to the full thickness of the plywood when the seam runs along a frame Set the width of the blade to shave the edges of both sheets of plywood at the joint and expose fresh wood on each edge Remove any fasteners in the way of the cut Be sure the wood is thoroughly dry Drive the fasteners deeper at the joint to allow for a valley to be sanded along the joint for the placement of one or more layers of fiberglass tape Sand a4 to 5 wide valley along the joint with a disc sander to allow the layer s of tape to lie below the surface Make the depression about 42 deep for each layer fiberglass tape that will fill the joint Use the sander or a chisel to remove any additional damaged or rotted plywood around the joint At an edge or chine use the sander or a router witha roundover bit to round the corner A 14 to radius will allow the glass tape to lie flat
105. oke of hardener Depress each pump head fully and allow the head to come completely back to the top before be ginning the next stroke Figure 8 4 Partial strokes will give the wrong ratio Read the pump instructions before using pumps Scrape corners 7 Figure 8 4 Dispense the proper proportions of resin Figure 8 5 Stir resin and hardener together thor and hardener oughly at least one minute longer in cooler tempera tures Before you use the first mixture on a project verify the proper ratio according to the in structions that come with the pumps Recheck the ratio anytime you experience prob lems with curing Dispensing without Mini Pumps Weight volume measure To measure 105 Resin and 205 or 206 Hardener by weight or volume combine 5 parts resin with 1 part hardener To measure 105 Resin and 207 or 209 Hardener by vol ume combine 3 parts resin with 1 part hardener by weight 3 5 parts resin 1 part hardener First time users Begin with a small test batch to get the feel for the mixing and cur ing process before applying the mixture to your project This will demonstrate the hardener s open time for the temperature you are working in and assure you that the resin hardener ratio is metered properly Mix small batches until you are confident of the mixture s handling characteristics Using WEST SYSTEM Epoxy 62 Mixing Stir the two ingredients together thoroughly at least one minute longer in cooler temperatur
106. ole with epoxy Keep the plasticine dam full as the epoxy soaks into the end grain in the hole 6 After the epoxy has cured sand the surface smooth remove the protective tape and replace the washers and nuts 7 Call Gougeon Brothers Inc for more specific discussion of repairing larger keels 27 Repairing Hull and Deck Planking 5 Repairing Hull and Deck Planking This section is a guide for the repair of the outer skin of wooden boats The skin covering the deck and hull framework of wooden boats can generally be divided into two categories planking and plywood Planking is the older traditional method of covering hulls and decks and is more susceptible to flexing and leaks than plywood Modern adhesives have made plywood a more common and practical skin for wooden structures The procedures in this section deal with the problems and repairs for the most common types of skins Select the procedure or combination of procedures that best fits your situation 5 1 Carvel planked hulls and laid plank decks For centuries carvel planking and laid plank decking were the only methods of enclosing a boat Carvel planking and laid plank decking are essentially the same method in which many individual boards are laid edge to edge fastened to each frame and caulked Eventually the structure loosens up the caulking breaks down and the planking becomes a constant source for leaks and endless maintenance While carvel hull planking and laid
107. olts a small silicone sealant fillet covering the joint between the cured epoxy and the fastener will protect against moisture and salt intrusion Of course any exposed metal surface will be subject to the effects of saltwater corrosion therefore proper maintenance and cleaning procedures must be practiced 6 1 Fastener bonding The fastener to wood bond can be done in several ways The easiest and most common method is simply to wet out a standard size pilot hole for a given fastener with resin hardener Make easy fastener bonds as follows 1 Use a pipe cleaner or syringe to work the mixture well into the hole Insert the fastener in the hole and allow the epoxy to cure This forms a wood epoxy matrix around the fastener that is much stronger than the wood by itself and distributes the fastener load over more of the wood fiber area 6 2 Hardware bonding You can further improve the load carrying capability of the hardware by increasing the amount of epoxy that surrounds the fastener taking advantage of the fact that WEST SYSTEMe epoxy has much higher density and strength than the wood fiber itself and bonding the hardware base directly to the surface Bond for increased load transfer as follows Installing Hardware 44 Epoxy squeeze out Epoxy Interface gt with penetration into endgrain Backing plate on thinner substrate Figure 6 1 A normal sized pilot hole at the bottom of the oversized Figure 6 2 Tighten
108. on On the surface moisture causes the top veneer to check Early plywood decks were protected with canvas laid ina fresh coat of paint or canvas cement The fabric may have offered some protection but 11 Inspecting and Evaluating because moisture can be trapped under a large area of the fabric serious damage can be done before it s discovered When you notice the soft deck or the loose fabric the plywood may have already lost much of its strength Hardware Besides the problems of joints in the deck itself deck hardware is a major source of deck leaks and moisture damage All deck hardware is anchored to the deck with mechanical fasteners that penetrate the skin Lightly loaded hardware may be simply screwed into the skin Hardware items that take high loads need to be screwed or bolted through the skin into a structural member e g a deck beam or extra blocking that can transfer the load over a larger area If all the mounting holes are not drilled precisely the fasteners holding the hardware in place will not share the load equally The hole with the most highly loaded fastener elongates as the hardware is stressed repeatedly Movement reduces the load carrying capacity of the wood fiber surrounding the fastener and creates an entry point for water Bedding compounds designed to seal out moisture between the hardware base and the deck surface do nothing to prevent movement of the hardware Over time this movement will break down the
109. ormation on bonding threaded rod 17 Repairing the Structural Framework 4 Repairing the Structural Framework Replace or reinforce in place framework that is too weak to carry its designed load Structural framework includes the keel stems hull frames stringers deck beams sheer clamps shelves knees carlins or thwarts They vary widely in size shape and position but have many problems and repair techniques in common Frames can be damaged from dry rot or from impact Under impact frames often break in multiples If you find a cracked frame take the time to look for others especially adjacent to the broken one Hull frames often break at stringer edges the turn of the bilge and at the reverse turn especially in the stern Examine the outside of the hull for a knuckle or unfair spot in the planking in the area where the frames are damaged If you find planks that are out of position temporarily force the affected planks and frames back using whatever means are available You may use bracing and shims on the outside of the hull and or rope and tackle on the inside The frame repair can begin once the shape of the hull is restored Frame repairs rely on replacing damaged frames or sections of frames with material that is of equal or greater strength see Appendix Wood data page 75 Laminating is an efficient method of building frames and a basic technique for the frame repairs in this Section 4 1 Laminating beams frames and
110. ot of fairing material to remove Use 80 grit paper on the appropriate sanding block when you are close to the final contour CAUTION Don t forget your dust mask Remove the sanding dust and fill any re maining voids following the same procedure aee Figure 8 16 Sand the fair ing material to blend with the surrounding contour 7 Apply several coats of resin hardener to the area with a disposable brush or roller after you are satisfied with the fairness Allow the final coat to cure thoroughly before final sanding and finishing 69 Using WEST SYSTEM Epoxy 8 4 5 Applying woven cloth and tape Fiberglass cloth is applied to surfaces to provide reinforcement and or abrasion resis tance or in the case of Douglas Fir plywood to prevent grain checking It is usually ap plied after fairing and shaping are completed and before the final coating operation It is also applied in multiple layers laminated and in combination with other materials to build composite parts Fiberglass cloth may be applied to surfaces by either of two methods The dry method refers to applying the cloth over a dry surface The wet method refers to ap plying the cloth to an epoxy coated surface often after the wet out coat becomes tacky which helps it cling to vertical or overhead surfaces Since this method makes it more difficult to position the cloth the dry method is the preferred method especially with thinner cloth Dry method 1
111. ould contact all three epoxy supports Allow the epoxy supports to cure thoroughly Tap the hardware with a mallet to break it loose and remove the temporary shims Mask off the area around the fitting with duct tape and plastic in case of accidental epoxy spills Prepare the deck and hardware for casting the base Wash and sand the cured epoxy in the deck base area Reapply mold release to the hardware base At this time mask off areas of the hardware that you don t want to come in contact with the epoxy You may also find it helpful to place small pieces of tape over the holes in the hardware item to prevent the epoxy mixture from oozing up through them when the piece is repositioned Apply enough thickened epoxy 404 peanut butter consistency to fill the entire base area If the base to be cast is more than 2 12mm thick you may want to use 206 Slow Hardener to reduce the possibility of exothermic heat buildup during the curing process Build up the mixture slightly taller than the base supports roughly forming the shape of the base Fill all voids around the epoxy supports Reset the hardware in its proper location Slowly press it into the proper position on top of the cast epoxy supports Allow excess epoxy mixture to squeeze out of the gap between the base of the hardware and the deck Sculpt the squeezed out mixture into the desired shape Figure 6 3b A standard fillet works well in this situation Section 8 4 3
112. ount when calculating hardware loads We recommend adhesive bonding to all hardware and fasteners rather than the use of mold release whenever possible 6 6 Removing bonded hardware Occasionally it is necessary to remove bonded hardware items At temperatures above 150 F 66 C cured epoxy begins to lose its physical properties the resin softens and its bonding capacity is reduced considerably You can use this characteristic to your advantage when you would like to remove a piece of bonded hardware Remove all fasteners If you used a release agent on them when you bonded the piece in place they should come loose without too much difficulty If the fasteners were bonded in it will be necessary to apply heat to them using a soldering iron The epoxy around the fastener will soften enough to loosen the fastener when enough heat is conducted down the fastener Heat the fitting briefly with a propane torch Protect the area around the fitting from heat damage by covering with water soaked plywood Allow the heat to conduct through the base of the hardware A sharp rap with a mallet should be enough to dislodge the hardware If the fitting doesn t break loose easily the first time don t force it Heat it a second time with the torch and try again Replace the hardware by following the procedures in Section 6 2 Redrill the fastener holes in the existing epoxy as you would for a new installation Protecting and Maintaining Wo
113. oxy safety 8 2 Epoxy products 8 3 Handling epoxy 8 4 Basic techniques Appendix WEST SYSTEM product estimating guides Problem solving guide Wood data Additional reading Index 43 43 45 46 47 47 48 50 51 52 54 54 55 56 59 63 72 73 75 77 78 1 Introduction 1 Introduction Since the early 1970s epoxy has been at the forefront of a revolution in boat building Wood has once again become the primary building material for many of today s fastest most durable and most beautiful boats both sail and power Many of the techniques of wood epoxy construction that have made modern wooden boats so successful can also be applied to the repair of older wooden boats with excellent results Wooden Boat Restoration amp Repair explains these techniques drawing on years of testing and experience at Gougeon Brothers Inc and the experiences of many individual builders The manual does not offer cheap easy or quick fixes for these are rarely satisfactory However it does offer reliable and thorough information for restoration and repair ranging from reinstalling a cleat to rebonding the entire boat The technical staff at Gougeon Brothers Inc have been helping customers with boat repair and restoration problems since the epoxy revolution began Whenever we talk to someone about a project we begin by asking the same basic questions v What type of construction is the boat v What condition is the boat in
114. place using the standard bonding techniques in Section 8 4 2 Many of the frames that can t be removed can still be bonded into place as follows 1 Support the boat in its proper shape before bonding any joints 2 Open as many of the joints as you can reach between frames and between frames and the outer skin Loosen fasteners wherever possible A small pry bar or wedge may be used to force the joint open temporarily Use a saw blade or other sharp tool to scrape out old paint varnish or dirt from the joints Figure 4 7 Clean the inner joint surfaces to bare wood as much as possible Figure 4 7 Use a scraping tool to clean out and abrade the inner Figured 4 8 Inject epoxy as far as possible into the joint joint surfaces 3 Wet out the inner contact areas of the joint Use a syringe small brush or pipe cleaner to reach the middle of the joint 4 Apply thickened epoxy to the contact area of the joint Use a syringe to inject an epoxy 406 filler mixture to the middle of the joint Figure 4 8 A small plastic tube or straw taped to the spout of the syringe will extend the reach of the syringe into a tight area Inject enough of the thickened mixture so that a small amount will squeeze out when the joint is clamped together 5 Clamp pieces in position until the epoxy cures Tighten fasteners to draw the joint closed Fasteners may be bonded in place for moisture protection and added strength see Section 6 4 6 Repairing garboar
115. plank decks vary in the size and placement of the planks they are similar in function and can be repaired with the same techniques As mentioned in Section 1 4 2 the ideal reconstruction would be to remove the planking clean and strip it of paint and bond it edge to edge and to the framing timbers If you can do this you can eliminate places where moisture can become trapped and could then coat both the inside and the outside of the hull with epoxy to encapsulate it Remember you can only encapsulate the boat with epoxy if all of the surfaces especially the contact surfaces of joints can be coated If however the framing is sound and you don t want to remove the planks your best solution to leaks and loss of stiffness is to 1 clean out the seams 2 bond the planks together with epoxy and 3 coat the exterior with epoxy and 4 ventilate the interior to reduce expansion and contraction This seals the seams permanently and eliminates movement between planks A strong bond between all the planks will result in a much more rigid structure IMPORTANT As a rule edge bond the planks only if you coat the exterior coat the exterior only if you edge bond the planks Edge bonding the planking and coating the exterior will stiffen the structure and reduce maintenance Below the waterline it will also stop water penetration through the hull help keep the interior drier and dry wood is stronger than wet wood It will allow the boat to be d
116. posed end grain A mixture using 206 Slow Hardener should penetrate more deeply than 205 hardener before it begins to gel Figure 3 4 Figure 3 4 Inject resin hardener mixture into holes until the Figure 3 5 Fill the remaining voids with fairing compound damaged wood absorbs all it can 4 Continue to add epoxy to the holes until the wood is saturated and can no longer absorb more 5 Fill remaining voids with thickened epoxy after the epoxy reaches its initial cure if desired Figure 3 5 Use an epoxy fairing filler mixture for cosmetic fairing of the surface see Section 8 4 4 Repairing Localized Dry Rot 16 3 2 1 Thinning epoxy There are epoxy based products specifically designed to penetrate and reinforce rotted wood These products basically an epoxy thinned with solvents do a good job of penetrating wood But the solvents compromise the strength and moisture barrier properties of the epoxy We are often asked if WEST SYSTEM epoxy can be thinned with solvents for greater penetration The answer is yes but not without the same compromise in strength and moisture resistance Laquer thinner Acetone and denatured alcohol have been used to thin WEST SYSTEM epoxy duplicating these penetrating epoxies with about the same effectiveness If you chose to thin the epoxy keep in mind that the strength and moisture protection of the epoxy are lost in proportion to the amount of solvent added Adding 5 laquer thinner results in a 60
117. pport the boat in its proper shape Stem and transom centerlines should be plumb The sheers should be level at each station Brace or shim the hull to prevent any movement before the repair is complete The more parts that are bonded with epoxy the more rigid the final structure will be When the repairs are complete the boat will retain the shape in which it was supported 2 Remove equipment hardware and accessories canvas covering trim and fiberglass cloth if it is loose 3 Find the sources of leaks and the areas affected by leaks before the boat dries out Look for damp areas peeling paint soft or discolored wood Remove the old finish as necessary to judge the condition of the wood underneath 4 Inspect each structural member and its fasteners to see if they can still carry their intended load Use an ice pick or other sharp tool to probe for areas of dry rot Look for rot in areas of poor air circulation where parts contact each other and around fasteners If the damage is from an impact or fatigue look for cracked frames or loose fasteners away from the obviously damaged area Figure 2 4 5 Remove damaged material and parts that block access to suspected damage As necessary dismantle the skin and underlying structure in reverse order of construction until all of the damage is removed or accessible Carefully remove and save salvageable parts for reassembly Some parts although damaged beyond repair may still serve as pattern
118. ral problems in wooden boats that are within the abilities of the amateur However before embarking ona major rebuilding operation it is important to evaluate your commitment carefully and determine your approach to repair and the time and money you are prepared to allocate to the project 1 1 1 Distinguish between repair and restoration Do you want your boat faithfully restored repaired to function and look good or patched and in the water as quickly as possible Repair means to fix broken parts to patch holes resulting from impact or moisture damage to strengthen weak spots or tighten loose parts If your goal is repair you do not need to commit yourself to a consistent repair method You can fix one part with epoxy and another part another way However you need to consider the effects of a repair on the overall structure For example bonding a plank in place with epoxy could cause high local stiffness in an otherwise flexible structure In some cases it may be better to repair the boat in the same fashion in which it was built rather than use different bonding and construction techniques Restoration means to bring a boat back to its original or better than original condition To restore a boat successfully you need to develop an overall approach to renovation and maintain consistency in reconstruction methods Any restoration is a major project that will involve much time dedication and careful planning 3 Introduction You
119. rdener together thoroughly to avoid resin rich and hardener rich areas 3 Add fillers or additives after resin and hardener have been thoroughly mixed Incorrect products Insufficient cure 1 Remove epoxy Do not apply additional material over non curing epoxy See 8 3 5 Removing epoxy 2 Check for proper resin and hardener Resin will not cure properly with other brands of hardener or with polyester catalysts See above Resin starved joint epoxy has wicked into porous surfaces leaving a void in the joint Wet out bonding surfaces before applying thickened epoxy Re wet very porous surfaces like end grain Contaminated bonding surface Bonding area too small for the load on the joint Too much clamping pres sure squeezed epoxy out of the joint Epoxy applied too thick Clean and sand the surface following the procedure on page 63 Section 8 4 1 Increase bonding area by adding fillets bonded fas teners or scarf joints See bonding note page 65 Use just enough clamping pressure to squeeze a small amount of epoxy from the joint 1 Use 800 Roller Covers and roll the coating out into a thinner film A thin film will flow out much smoother than a thicker film after it is tipped off with the foam roller brush 2 Warm the epoxy to thin it or apply the coating at a warmer temperature Coating curing too slowly 1 Apply the coating at a warmer temperature 2 Warm the resin and
120. reduction in viscosity It also reduces epoxy s compressive strength by 35 There is a better solution to get good penetration without losing strength or moisture resistance We recommend moderate heating of the repair area with a heat gun or heat lamp to about 115 F still comfortable to touch The epoxy will have a lower viscosity and penetrate more deeply when it is warmed by contact with the warmed wood cavities and pores In addition heat will expand air in the wood pores causing it to out gas When the heat is the removed the cooling wood will draw epoxy back in Slower hardeners 206 207 209 will have a longer working life and should penetrate more than 205 Hardener before they begin to gel When the epoxy cures it will retain all of its strength and effectiveness as a moisture barrier which we feel more than offsets any advantages gained by adding solvents to the epoxy 3 3 Reinforcing Tensile strength can be added to a dry rot repair area by using synthetic fiber such as fiberglass carbon fiber or Kevlar in appropriate amounts with epoxy Refer to Section 8 4 5 for application information Apply the reinforcing after the dry rot has been excavated and filled or drilled and filled Stainless steel threaded rod has also been used to reinforce and join pieces with excellent results The rod can be bonded into drilled or grooved pieces as a structural pin to tie individual or separate pieces together See Section 6 4 for inf
121. rfaces of joints can be coated To repair double planking Carefully label the outer layer of planking for position and remove it Decide if the planks are worth saving If so clean dry repair and sand them Remove and discard the canvas between the layers of planking Follow the procedures described in 5 1 1 5 1 4 to clean out the seams and bond the layer of planking still on the hull Bond the second layer of planking following techniques discussed in 8 4 2 You can use screws in the old screw holes to hold the planks in place while the epoxy cures 5 1 6 Repairing Tongue and Groove Deck Planking The methods described previously are also applicable to tongue and groove deck planking 1 Clean the seams to the tongue 2 Ifaccess is possible and the tongue is loose or broken tape the underside of the seams 3 Force thickened epoxy 403 or 406 mayonnaise consistency as thoroughly into the seams as possible This mixture forced with a 5 wide putty knife can flow about the tongue and groove joint and into the underside seam thereby achieving a complete bond of the mating planks 5 2 Lapstrake Planked Hulls 1 Lapstrake or clinker like carvel planking is composed of a single layer of planks thin enough to bend to the shape of the hull However each plank or strake overlaps the face of the preceding plank rather than butting the edge of it Wooden lapstrake hulls often have trouble with the lap fas
122. ry sailed no longer relying on the planks to swell before it is water tight In many cases it is advisable to make this repair below the water line only Often it is the first stage in a restoration or it may be the only improvement to an otherwise sound boat Repairing Hull and Deck Planking 28 5 1 1 Cleaning out the seams Getting a good clean bonding surface on each plank edge is the first step You can use a circular saw a router a chisel and hammer or a sharpened scraper to clean all the old caulking material out of the joint and expose clean fresh wood for bonding on the facing edge of each plank One tool may work better than another in a given situation but a circular saw is usually the most effective way to mill out the seam accurately 1 Dry the hull thoroughly before beginning This allows the seams to open to their widest and stabilizes the size and shape of all the pieces 2 Tack a batten to the hull to act as a guide for the saw The batten should be parallel to the seam so the blade will follow the center of each seam exactly 3 Select a blade or reset the blade s teeth wide enough to shave the edges of both planks facing the seam Use a pair of pliers to bend the teeth for more set The seam width may vary but the cut should be at least 36 If the seams have opened very wide after drying two passes with the saw may be necessary to shave both planks 4 Set the depth of the cut to 4 less than the thickness of the pl
123. s for fashioning a replacement Removing the damage does not necessarily mean removing the entire part Often a part can be repaired in place by scarfing in a a new section or adding reinforcing see Section 4 3 6 Dry the boat thoroughly before beginning repairs Remove all the remaining old finish and provide plenty of ventilation to speed the drying process The wood moisture content should equilibrate at 8 12 The structure will then be dimensionally stable the epoxy will bond better and the moisture won t be sealed in Provide a dry sheltered work area for the boat and yourself Reassess the project Once you ve completed your inspection you ll know exactly what condition your boat is in and will be better able to plan your repair We urge you to again consider the questions posed in Section 1 v What results are you looking for A quick repair a complete restoration or something in between v Are you prepared to commit the time and resources to get the results you re looking for v Is wood epoxy construction the best solution to your problem When you are clear on your answers to these questions you are ready to proceed on your repair or restoration and use the following sections of this manual as appropriate Section 8 provides fundamental techniques for using WEST SYSTEM epoxy products successfully in wooden boat repairs Even if you are familiar with these products it is important to make sure you thoroughly understan
124. s one side of the hull and deck forward and the other side aft Other loads come from lifting the boat for storage adding cargo and stressing the rigging under sail Thus a boat is under a constant state of twisting stretching and flexing All of the joints must resist this flexing to keep the structure rigid and watertight The smallest movement around a fastener can weaken the fastener s holding power leading to more flexibility Over time every exterior joint that can flex is a potential source of moisture penetration Traditional caulking methods are intended to flex and absorb the movement between adjoining pieces but with the continual flexing these caulking materials will eventually break down Without regular maintenance the caulked joints will leak Then high moisture content of the wood around the joint leads to loss of wood strength see Appendix Wood data page 75 loss of fastener holding power more flexibility and even more moisture penetration An often repeated misconception about wooden boats suggests that it is their nature to be flexible and that flexibility is desirable because it contributes to the soft ride that makes wooden boats appealing But as those who race boats know a flexible boat absorbs power It is harder to push through the water than a stiff boat and for the reasons stated above it is not as durable A stiff hull is faster more efficient and more durable in the long run A soft ride is better a
125. s resin hard ener mixtures reach full cure Refer to product labels or Material Safety Data Sheets for specific product warnings and safety information Precautions 1 Avoid contact with resin hardeners mixed epoxy and sanding dust from epoxy that is not fully cured Wear protective gloves and clothing whenever you handle WEST SYS TEM Epoxies Barrier skin creams provide additional protection If you do get resin hardener or mixed epoxy on your skin remove it as soon as possible Resin is not water soluble use a waterless skin cleanser to remove resin or mixed epoxy from your skin Hardener is water soluble wash with soap and warm water to remove hardener or sanding dust from your skin Always wash thoroughly with soap and warm water after using epoxy Never use solvents to remove epoxy from your skin Stop using the product if you develop a reaction Resume work only after the symp toms disappear usually after several days When you resume work improve your safety precautions to prevent exposure to epoxy its vapors and sanding dust If prob lems persist discontinue use and consult a physician Protect your eyes from contact with resin hardeners mixed epoxy and sanding dust by wearing appropriate eye protection If contact occurs immediately flush the eyes with water under low pressure for 15 minutes If discomfort persists seek medical attention 3 Avoid breathing concentrated vapors and sanding dust WEST SYSTEM epox
126. s the original Cut the panel to the outside dimensions of the bevel or step a Use the disc sander to machine a bevel on the inside edge of the replacement panel to match the bevel on the opening Dry fit the new panel to fit slightly below the existing surface Figure 5 13 b Use the router with the straight fluted bit to machine steps in the edges of the replacement panel to match the steps around the opening If multiple layers of Repairing Hull and Deck Planking 36 plywood are to be used cut one layer to the dimension of each step Dry fit the new panel to fit slightly below the existing surface Wet out the bonding area of the panels with resin hardener mixture Recoat the end grain as necessary Plywood end grain will absorb a lot of epoxy Apply thickened epoxy 403 or 406 mayonnaise consistency to the new panel s bonding area Apply enough thickened epoxy so that a small amount will squeeze out when you push the new panel into its dry fit position Clamp the new panel in position with temporary staples or screws Permanent fasteners should be non corroding and pilot holes should be wet out with epoxy Clean up excess epoxy before it cures Allow the epoxy to cure thoroughly before removing clamps Bond multiple thinner layers in place one at a time following the same procedure Use a thinner epoxy mixture on the flat bonding areas between the layers Sand the surface and fill low areas with epoxy 407 or 410
127. side and out By coating every surface of every piece of wood in the boat with at least two coats of epoxy the moisture content of each piece remains at a constant level far below the fiber saturation level and the structure is dimensionally stable Encapsulating is easy to accomplish while building a new boat because every piece can be coated at the most convenient point before or after it is bonded in place Especially important is being able to coat pieces or surfaces that can no longer be reached once the structure is assembled Encapsulating an older or conventionally built boat is not possible unless all of the surfaces especially the contact surfaces of joints can be coated This would involve 7 Introduction disassembling the boat piece by piece and bonding it back together You ll have to decide if your boat is worth this much effort However even if you cannot encapsulate the entire boat you can look for structural units that might be encapsulated You might be able to encapsulate some areas by removing and bonding one piece at a time Can I coat the inside of my boat with epoxy is a question often asked In most cases you are better off not coating the interior Just to coat as many surfaces of the interior as you can reach leaves many uncoated surfaces and is not the same as encapsulating since it does not ensure a continuous unbroken moisture barrier and will not eliminate joint movement or prevent moisture from enterin
128. surfaces and to prevent resin starved joints Apply enough of the mixture to one of the surfaces so that a small amount will squeeze out when the surfaces are joined together with a force equivalent to a firm hand grip Figure 8 9 Thickened epoxy can be applied immediately over the wet out surface or any time before the wet out is no longer tacky For most small bonding operations add the filler to the resin hardener mixture remaining in the batch that was used for the wet out Mix enough resin hardener for both steps Add the filler quickly after the surface is wet out and allow for a shorter working life of the mixture 3 Clamp components Attach clamps as necessary to hold the components in place Use just enough clamping pressure to squeeze a small amount of the epoxy mixture from the joint indicating that the epoxy is making good contact with both mating surfaces Figure 8 10 Avoid using too much clamping pressure which can squeeze all of the epoxy mixture out of the joint Figure 8 10 Clamp components in place before the Figure 8 11 Remove or shape excess epoxy that epoxy gels squeezes out of the joint 4 Remove or shape excess adhesive that squeezes out of the joint as soon as the joint is secured with clamps A wooden mixing stick with one end sanded to a chisel edge is an ideal tool for removing the excess Figure 8 11 Single step bonding Single step bonding is applying the thickened epoxy directly to both bonding surf
129. tch begins to gel Smooth wrinkles and position the cloth as you work your way to the edges Check for dry areas especially over porous surfaces and re wet them as necessary before pro ceeding to the next step If you have to cut a pleat or notch in the cloth to lay it flat ona compound curve or corner make the cut with a pair of sharp scissors and overlap the edges for now Using WEST SYSTEM Epoxy 70 NOTE For clear wood finishes an alternative wet out method is to lay the epoxy onto the fabric with a short bristled brush Dip the brush in the epoxy and lay the epoxy on the surface in a light even stroke Don t force the epoxy into the cloth which may trap air in the fabric and show through the clear finish Apply enough epoxy to saturate the fabric and the wood below After several minutes lay on additional epoxy to dry white areas 7 Squeegee away excess epoxy before the first batch begins to gel Figure 8 18 Drag the spreader over the fabric using even pressured overlapping strokes Use enough pres sure to remove excess epoxy that would allow the cloth to float off the surface but not enough pressure to create dry spots Excess epoxy appears as a shiny area while a properly wet out surface appears evenly transparent with a smooth cloth texture Later coats of epoxy will fill the weave of the cloth 8 Trim the excess and overlapped cloth after the epoxy has reached its initial cure The cloth will cut easily with a sharp
130. teners working seams open causing leaks The most successful repair is to clean out the lapped seams and bond the planks together with epoxy It will be very helpful to work on your boat upside down if it is small enough to turn over Repair lapstrake hulls as follows Remove all paint or old finish on the outside of the hull 33 Repairing Hull and Deck Planking Figure 5 8 Clean out the seams with a scraper Figure 5 9 Fill the wet out seam with thickened epoxy 2 Scrape the old paint and caulk out of all the seams Use a custom scraping tool to clean out and abrade the plank mating surfaces down to bare wood Figure 5 8 A file with the tang bent and sharpened or a hacksaw blade makes an excellent seam scraper Allow the wood to dry thoroughly if it has not already dried Support the hull in its proper shape before beginning bonding There is typically a transition from the lap to a rabbet where the planking laps run into the stem or transom This allows the planks to lie flush with each other and fair with the stem When cleaning out the laps pay attention to this transition zone It may be necessary to remove fasteners at the ends of the planks and open them slightly to clean out the seams and the rabbets Wet out the opened seam surfaces with resin hardener mixture Work epoxy into the seam as deeply as possible with a disposable brush or syringe Apply thickened epoxy 403 or 406 peanut butter consistency into the op
131. ter a long storage to verify the metering accuracy of the pumps and mix a test batch to assure proper curing be fore applying epoxy to your project 73 Problem solving guide Problem solving guide This guide is designed to help identify and prevent potential problems associated with using epoxy If the solutions described here do not resolve the problem call the Gougeon technical staff PROBLEM The epoxy mixture has not cured after the rec ommended cure time has passed Bond failure Runs or sags in coating POSSIBLE CAUSES Off ratio Too much or too little hardener will affect the cure time and thor oughness of the cure SOLUTION 1 Remove epoxy Do not apply additional material over non curing epoxy See 8 3 5 Removing epoxy 2 Check correct number of pump strokes use equal strokes of resin and hardener DO NOT add extra hardener for faster cure 3 Check pump ratio see pump instructions 4 Check for correct pump 5 1 or 3 1 ratio and pump group size Group B resin and Group B hard ener Low temperature Epoxy mixtures cure slower at low temperatures 1 Allow extra curing time in cool weather 2 Apply heat to maintain the chemical reaction and speed the cure 3 Use a faster hardener designed to cure at lower temperatures Insufficient mixing 1 Remove epoxy Do not apply additional material over non curing epoxy See 8 3 5 Removing epoxy 2 Mix resin and ha
132. the compound as you are applying it If it is too thick it will be difficult to apply in a controlled thin film and cause some buildup on the surface If it is too thin you will lose filling power However it is better if the compound is on the thin side because you can always apply another coat if the first was not sufficient and this is faster than sanding You can control surfacing compound consistency by adding the manufacturer recommended amount of thinner You may have to do this at regular intervals to make up for the evaporation of thinner as you apply the compound For best results use a drywaller s taping knife 6 to 8 wide Make sure that the surface to which you are applying the compound is clean We find that we rarely need primer paints when we coat hulls with WEST SYSTEM epoxy Primers can t of course be used on naturally finished hulls but even on painted surfaces they don t greatly reduce finishing time Primers are not usually needed to help bond a paint film to a cured WEST SYSTEM epoxy surface Most finish coatings adhere to an epoxy coated surface that has been sanded well although interfacing primers are required with some specialized bottom paints If the instructions on your paint or varnish recommend a primed surface sand the epoxy coating until it is no longer glossy and follow the directions given by the manufacturer for preparation Test the product in an inconspicuous area to be sure that it will bond to epo
133. thickened to the ex act consistency needed for a particular job The procedures in this man ual refer to four com mon consistencies syrup catsup mayon naise and peanut butter Maximum thickness PEANUT BUTTER Unthickened mixture Slightly thickened CATSUP Moderately thickened MAYONNAISE CONSISTENCY GENERAL APPEARANCE CHARACTERISTICS Drips off vertical sur faces Sags down vertical sur faces Clings to vertical sur faces peaks fall over Clings to vertical sur faces peaks stand up Coating wetting out before bonding apply ing fiberglass graphite Laminating bonding flat panels with large sur face areas injecting General bonding fillet ing hardware bonding Gap filling filleting fair ing bonding uneven surfaces and other fabrics with a syringe Always add fillers in a two step process 1 Mix the desired quantity of resin and hardener thoroughly before adding fillers Begin with a small batch allow room for the filler 2 Blend in small handfuls or scoops of the appropriate filler until the desired consistency is reached Figure 8 7 For maximum strength add only enough filler to completely bridge gaps between sur faces without sagging or running out of the joint or gap A small amount should squeeze out of joints when clamped For thick mixtures don t fill the mixing cup more than 1 3 full of epoxy before adding filler When making
134. thin coats The thinner the film the easier it is to keep it even and prevent runs and sags 4 Apply a third coat while the second coat is still slightly tacky You can add any number of coats to build up the desired coating thickness while the previous coat is still slightly tacky Be sure to level out each fresh coating with the foam brush 5 Allow these coats to cure fully The cure can be accelerated with moderate heat but too much heat may cause bubbling Figure 7 5 Wet sand to a smooth finish Figure 7 6 Rinse water should sheet without beading indicating an uncontaminated surface 6 Wet sand the cured 105 207 epoxy surface to a 220 grit or finer finish Figure 7 5 Rinse the surface with clean water Rinse water should sheet evenly without beading or fisheyeing If rinse water beads up a sign of contamination wipe the area with solvent and dry with paper towels then wet sand again until beading is eliminated Proceed with the finish coating after the surface has died thoroughly See Section 8 4 1 Surface preparation Special preparation for various materials Cured epoxy 7 3 Clear finish coatings Even though a properly applied 105 207 coating may have a high gloss finish equal to that of a good varnish we recommend that this surface be coated with a top quality spar varnish for UV protection and maximum performance Two part polyurethanes bond well to cured WEST SYSTEM epoxy surfaces and provide great hardness and 7 4
135. ting and replace any paint or varnish used over it Touch up dings to the varnish or paint to maintain their effective moisture and UV barriers Plan to apply a new coat of varnish every year or two The linear polyester polyurethane coatings do not take buffing like a gelcoat so we recommend careful application The acrylic polyurethanes can be buffed but seem less durable 7 6 Ventilation for longevity Ventilation is a key factor in the continued longevity of your boat Keeping the boat s interior as dry as possible is the best preventive maintenance for preserving the structure and making the boat more comfortable Keep the bilges as dry as possible This is a good idea whether or not you have coated the bilges with epoxy Make sure that drainage is good and that there are no hidden areas in the bilges where water can lie Limber holes should be large and open For safety and longer coating life keep fuel and oil out of the bilges An open interior layout is better for ventilation Do not let clutter build up See that no water absorbent materials leaves or clothing are in contact with the hull or interior joiner work Watertight deck or cabin openings and effective ventilators with good drainage such as dorade boxes or mushrooms can make the boat more comfortable when in use and drier at the dock or mooring If using a fabric mooring cover vents are available that can be sewn or snapped into the cover fabric to provide ventilation
136. tion amp Repair approaches a repair project in several phases Section 1 provides guidelines for assessing the feasibility of repair and restoration provides an overview of problems typically encountered in wooden boats and explains the major uses of epoxy in repair Section 2 discusses how you can evaluate the soundness of your boat s structure and locate damaged areas Sections 3 4 5 and 6 provide detailed procedures for the most common types of repairs These sections can be used in whatever order your repair requires Section 7 discusses how to protect against UV finish and maintain wooden boats Section 8 provides fundamental techniques for using WEST SYSTEM epoxy products successfully in wooden boat repairs including surface preparation bonding bonding with fillets laminating fairing applying woven cloth and tape final coating and finishing Particularly if you have not used WEST SYSTEM products before it is important to read this section carefully before beginning any of the repairs discussed in previous sections Following the procedures described in Wooden Boat Restoration Repair will allow you to restore the primary functions of the boat s structure reduce flexing and provide moisture protection They will assure thorough long lasting repairs for boats or other wooden structures 1 1 Assessing the feasibility of repair and restoration The repair methods in this manual offer practical solutions to structu
137. tside of the margin Figure 8 12 Use the excess material to re fill any voids Smooth the fillet until you are satisfied with its appearance A mixing stick will leave a fillet with about a radius For larger fillets an 808 Flexible Spreader cut to shape or bent to the desired radius works well Apply additional thickened epoxy to fill voids or make larger fillets Apply the mixture along the joint line with the rounded mixing stick using enough mixture to create the desired size of fillet For longer or multiple fillets empty caulking gun cartridges or disposable cake decorating bags can be used Cut the plastic tip to lay a bead of thickened epoxy large enough for the desired fillet size Heavy duty sealable food storage bags with one corner cut off may also be used Figure 8 12 Shape and smooth the fillet with a Figure 8 13 Clean up the excess epoxy outside of the rounded filleting tool fillet margin 3 Clean up the remaining excess material outside of the margin by using a sharpened mixing stick or a putty knife Figure 8 13 Fiberglass cloth or tape may be applied over the fillet area before the fillet has cured or after the fillet is cured and sanded 4 Sand smooth with 80 grit sandpaper after the fillet has fully cured Wipe the surface clean of any dust and apply several coats of resin hardener over the entire fillet area before final finishing Using WEST SYSTEM Epoxy 68 8 4 4 Fairing Fairing refers to the filling
138. uch fittings Unfortunately wooden shims require a great deal of time and carpentry skill Hardware casting can save time and is easy to do more importantly it can result in a stronger waterproof base Cast the hardware at an angle to the surface as follows Prepare the bonding surfaces Clean the substrate and hardware bonding surfaces with solvent to remove any contaminants Sand the deck with 50 grit sandpaper Apply a release agent such as an automobile wax or a non stick cooking spray to the base of the hardware Position the hardware Mark the outline of the hardware and shim it to its desired angle Mark the shim locations Often one edge of the fitting will rest on the deck and become the zero point for the required angle Wet out the substrate deck surface with resin hardener mixture except for the shim locations Cast epoxy supports under the hardware Figure 6 3a Prepare a mixture of resin hardener 404 High Density filler peanut butter consistency Use the mixing stick to place three portions of the mixture within the hardware outline evenly spaced around the perimeter Use enough of the mixture and pile the mixture high enough to contact the base of the hardware when it is shimmed in its proper position When cured the epoxy supports will take the place of the temporary shims Set the fitting in place with the temporary shims holding the hardware at the proper height and angle The bottom of the hardware sh
139. upport the hull in its proper shape before bonding The shape of the hull will be permanently set once the planks are bonded 1 Prepare the splines Cut them from stock that is the same species and thickness as the planking Rip the splines on a table saw with the blade set at a 5 angle Flip the stock end for end after each pass so each spline will have a 10 taper in cross section Set the width of the cut so that the wide end of the taper is the same width as the seam gap It should fit snugly when pushed into the gap just as the narrow end hits the bottom of the gap The splines can be any convenient length for easy handling Cut a 45 scarf on the ends of each spline Figure 5 5 Inject epoxy into the wet out seam 2 Wet out an equal length of opened seams and splines with resin hardener mixture Use a glue brush or swab to wet out the seam Use a foam roller cut to a narrow width to wet out the splines 3 Apply a bead of epoxy 403 or 406 mayonnaise consistency in the seam Use a syringe or an 810 Caulking Tube to fill the gap with enough epoxy so that a small amount will squeeze out when the splines are pushed in Figure 5 3 Ltd hy firs Figure 5 3 Push the wet out spline into the seam Figure 5 4 Use a plane to remove the excess spline and a sander to fair the surface after the epoxy has cured Repairing Hull and Deck Planking 30 Push the wet out spline into the seam Figure 5 4 The taper on the spline should
140. with either brush or spray application some solvents will escape into the atmosphere Without adequate ventilation of the painting area solvent fumes from any type of paint system can be dangerous and uncomfortable to breathe 7 4 1 Surface glazing 7 4 2 Primers Glazing or surfacing compounds often reduce finishing time These products are much thinner than standard puttying fillers so you can apply them quickly ina thin film over large areas We recommend using a wide putty knife or spreader to apply surfacer This technique results in a smooth surface which is not difficult to sand to a fine finish Since small particles of dirt can interfere with your finish be sure your wood is clean before applying these products Surfacing compounds have an advantage over primer paints in that surfacers are high solids materials and can be used easily to fill small voids and depressions in a cured resin surface Often the choice is between sanding away small air holes and valleys or filling them Extra sanding takes time and may remove too much protective coating so surfacing compounds are a good alternative Paint companies market surfacing compounds with instructions for their use If you will be using a linear polyurethane LP paint system be sure to select a surfacer which can be used under the paint LP paint systems use aggressive solvents which can lift some coatings or fillers When using surfacing compounds be aware of the consistency of
141. xy If any product fails to dry within the period specified on its packaging try a different brand or use a primer Protecting and Maintaining Wooden Boats 54 Primers are sometimes used to make sanding quicker The theory is that primers are easier to sand than epoxy while this may be true in some situations you must weigh the benefit against the time needed to apply the primer and to get an even surface Primers are difficult to apply evenly with a roller or brush are unsafe to spray and do not flow out as well as WEST SYSTEM epoxy so a good deal of sanding is needed just to get the primer as smooth as the original rough sanded epoxy surface A colored base coat will ease final fairing by serving as a guide to prevent oversanding and will also reduce the number of coats of paint needed to cover an unpainted surface When we plan to paint a hull we add WEST SYSTEM Color Pigment to our final coat of epoxy and use this instead of primer as a tracer coat 7 5 Repairing dings and cracks After repair or restoration continue to inspect your boat carefully for damage Look for hairline cracks at the joints There will probably be some in the first year after the repair See if boat flexure is the source of the crack or if moisture intrusion is causing expansion and cracking You do not need to repair these cracks instantly When you pull out your boat in the fall sand or scrape the cracks slightly and allow the area to dry Repair the epoxy coa
142. xy products Because physical properties of resins systems and epoxy brands vary using the techniques in this publication with coatings or adhesives other than WEST SYSTEM is not recommended This manual is updated as products and techniques change If the last copyright date below is more than several years old contact your WEST SYSTEM dealer or Gougeon Brothers Inc for a current version The information presented herein is believed to be reliable as of publication date but we cannot guarantee its accuracy in light of possible new discoveries Because Gougeon Brothers Inc cannot control the use of WEST SYSTEM Brand products in customer possession we do not make any warranty of merchantability or any warranty of fitness for a particular use or purpose In no event shall Gougeon Brothers Inc be liable for incidental or consequential damages WEST SYSTEM and Gougeon Brothers are registered trademarks and Microlight and Episize are trademarks of Gougeon Brothers Inc Bay City Michigan USA Copyright September 1990 December 1992 June 1997 May 1999 September 2000 April 2003 by Gougeon Brothers Inc All rights reserved No part of the contents of this book may be reproduced or transmitted in any form or by any means without the written permission of the publisher Published by Gougeon Brothers Inc PO Box 908 Bay City MI 48707 USA Printed 4 03 Cover photo sequence Restoration of the 1922 gaff rigged sloop REEB by Chris

Wooden Boat Restoration & Repair

Contents

Download Pdf Manuals

Related Search

Related Contents

Wooden Boat Restoration &amp; Repair

Contents

Download Pdf Manuals

Related Search

Related Contents

Wooden Boat Restoration & Repair