Spray gun Maintenance and Troubleshooting Guide (JGA)
Contents
1. a smear of Vaseline to all air O rings to aid fitting and easy rotation 4 Check gun body for damage particularly around air inlet connector port 5 Check stainless steel head fluid insert if fitted for damage to fluid tip seat swaging or leaks caused by rotation This item is not removable or replaceable and a new gun body will be necessary 6 Check for damage to air baffle chimney Replace air baffle assembly if necessary 7 Apply Vaseline to air valve spring to aid corrosion and contamination resistance ITW DeVilbiss UK Technical Training Centre ITW DeVilbiss Ringwood Road Bournemouth BH11 9LH Steve Mannouch Oct96 Tel 01202 571111 MAINTENANCE 8 TROUBLESHOOTING PAGE 82. Air leak from baffle seal Baffle seal swollen or damaged Unable to turn air control valve on Internal O ring swollen or broken Replace O ring handle of gun Paint contamination on threads Remove and thoroughly clean ez I o MAINTENANCE amp TROUBLESHOOTING PAGE 6 MAINTENANCE amp TROUBLESHOOTING Spray Gun Cleaning Suction Feed Clean Up Turn off air supply Disconnect cup from lid Raise tube out of material and pull trigger to allow remaining material to drain back into the cup Then empty the cup of material Clean the cup lid and tube Add some thinner to cup Reassemble Turn on air supply and spray with proper cleaning solvent Repeat with clean solvent if necessary Remove solvent disconnect gun remove air cap and clean Wipe gun and cup with cleaning solvent dampened rag Pressure Feed Clean Up First turn off air supply to material source cup tank or pump Release material pressure from the system by opening relief valve or pulling trigger on gun On a pressure cup or tank material in hoses may be drained back Lid must be loose and all air pressure off Keep gun higher than container and pull trigger Allow material to drain back into the container Pour off remaining material A hose cleaner can be used to clean inside of fluid hose gun and fluid tube in cup or tank Connect fluid hose to hose cleaner Open air valve at hose cleaner Pull trigger on gun and slowly open cleaning solvent valve on h
3. MAINTENANCE amp TROUBLESHOOTING PAGE 1 Spray gun Maintenance and Troubleshooting Guide F UK Technical Training Centre JGA IMPORTANT Before using the gun for the first time tighten the needle packing until the needle starts to bind Then loosen the packing nut just WARNING enough so that the needle moves freely The following hazards may occur during the normal use of this equipment Please read the following chart before using the equipment Area Hazard Safeguard Tells where hazards may occur Tells where hazard is Tells how to avoid the hazard Spray Area Solvent and coatings can be highly Adequate exhaust must be provided to Fire Hazard flammable or combustible especially keep air free of accumulations of flammable when sprayed vapours Smoking must never be allowed in the spray area Fire extinguishing equipment must be present in the spray area During cleaning and flushing solvents Wear eye protection can be forcefully expelled from fluid and air passageways Some solvents can cause eye injury Certain materials may be harmful if Follow the requirements of the Material inhaled or if there is contact with the Safety Data Sheet supplied by your coating skin material manufacturer Adequate exhaust must be provided to keep the air free of accumulations of toxic materials Use a mask or respirator whenever there is a chance of inhaling sprayed materials This mask must be compatible
4. acking for fluid leakage If required tighten the needle packing by rotating packing screw until the needle starts to bind then loosen the packing nut just enough so that the needle moves freely If screw bottoms without eliminating fluid leak replace packing with new item B Additional end of week maintenance checks 1 Check air cap retaining ring and gun air baffle threads are free from damage a smear of Vaseline on the threads will help prevent binding 2 Check air baffle seal is not leaking air badly or visibly damaged Replace if necessary 3 Apply smear of Vaseline to needle shaft front end for smooth operation 4 Apply Vaseline to needle shaft rear end and needle spring to aid corrosion and contamination resistance 5 Check Horn control valve is free to rotate with no stiff spots Lubricate or replace O ring if necessary 6 Check Air control valve if fitted is free to rotate with no stiff spots Lubricate or replace O ring if necessary 7 Check for air leaks from aircap when gun is not triggered Clean or replace air valve stem or seat if necessary 8 Check Trigger retaining screw is tight 9 Check fluid and air inlet connectors are tight and sealed Tighten if necessary C Additional Bi weekly maintenance checks 1 Check for air leakage from air valve body when trigger is pulled Replace air valve seal if necessary 2 Check fluid needle shaft is not badly worn and needle end profile and point are undamaged 3 Apply
5. ng Fluid Needle Air Valve Spring Oil Fluid Needle To Lubricate Packing S Air Valve Packing Daily or after each use if intermittent place a drop of SSL 10 gun lube on the points shown Springs behind the fluid needle and air valve should have a light coat of petroleum jelly PAGE 7 MAINTENANCE amp TROUBLESHOOTING PAGE 8 JGA Spray Gun Maintenance Schedule A Every Shift 1 Check front air cap face and all air cap holes are free from damage Replace if necessary 2 Check fluid tip external profile is undamaged Replace if necessary 4 Check fluid needle is seating correctly in fluid head allowing no seepage Replace or lap in if necessary 5 Turn off pressure tank fluid cock and or compressed air supply to gun Trigger gun Apply one drop of spray gun lubricant to needle shaft immediately behind fluid needle packing screw Release trigger Repeatedly pull and release trigger to work lubricant into fluid needle packing 6 Check trigger operates smoothly and fluid needle does not stick or bind up during movement due to damage or paint build up 7 Apply single drop of lubricant to each side of trigger pivot screw Repeatedly pull and release trigger to work lubricant into trigger pivot 8 Apply single drop of lubricant to air valve stem Repeatedly pull and release trigger to work lubricant into air valve packing seal 9 Check air valve operates smoothly without sticking Replace valve stem if necessary 10 Check needle p
6. ollow paint manufacturers instructions mixing Check distance normally 6 8 Increase air pressure or reduce fluid pressure Follow paint manufacturers instructions mixing Follow paint manufacturers instructions mixing Properly clean and prepare PAGE 3 MAINTENANCE amp TROUBLESHOOTING PAGE 4 MAINTENANCE amp TROUBLESHOOTING PAGE 4 MAINTENANCE amp TROUBLESHOOTING PAGE 5 GUN FAULTS Condition Cuse Correction Will not spray No air pressure at gun Check air supply and air lines Internal mix or pressure feed air cap used Change to proper suction feed air cap with suction feed Fluid pressure too low with internal mix Increase fluid pressure at tank cap and pressure tank Fluid needle adjusting screw not open Open fluid needle adjusting screw enough Fluid too heavy for suction feed Thin material or change to pressure feed Gun spits paint when triggering on Incorrect needle fitted to gun Check tip needle selection chart and fit and off correct item Excessive needle wear Replace with new needle Excessive fluid tip wear Replace with new fluid tip Small air leak from air cap when Air valve contaminated and not correctly Remove valve and thorougly clean valve gun is not triggered seating shaft and seating surfaces Air Valve seal damaged or missing Replace Gun spits paint when triggering on Fluid tip not fitted correctly in gun head Tighten to correct torque due
7. ose cleaner Flush until clean Shut off mixing valve when solvent and air discharge is clear Allow air to dry passages and then shut air valve at hose cleaner Repeat with hose to cup or tank connected to hose cleaner Lid on cup or tank should be set to one side of the shell or on a waste container Note This cannot be done with a pump Pump must be run with proper solvent to clean Clean inside of container and lid Wipe down gun with cleaning solvent dampened rag then lubricate Use SSL 10 spray gun lube MAINTENANCE amp TROUBLESHOOTING PAGE 7 Without a hose cleaner remove excess material from cup or tank and clean Set up cup tank or pump to operate with clean cleaning solvent Turn off atomisation air to gun Trigger gun into waste container Continue flushing until cleaning solvent is clear Blow air through hose to dry Wipe hose and gun with cleaning solvent dampened rag and lubricate gun Cleaning the Air Cap Remove the air cap and if dirtied with dry paint let it soak in clean solvent Later brush and wipe off the air cap If any holes in the cap are clogged probe them with a whittled match stick or tooth pick Don t ream the air cap holes with wire nails or metal tools This may damage the hole and result in imperfect spray patterns Note Never soak the entire gun in cleaning solvent This will dry out the packing and remove lubrication Lubrication Trigger Bearing Fluid Needle Stud Packi
8. replace as necessary Air valve sluggish or slow to turn Air valve stem bent Replace damaged component on off when trigger is pulled released Contamination on air valve stem Remove and clean D Air leak from around air valve stem Air valve seal damaged or missing Replace Air valve will not operate air valve Air valve stem bent Remove air valve and replace damaged air stem will not fully slide into valve valve stem body when trigger is pulled Contamination on air valve stem Remove air valve and thoroughly clean Stiff trigger action Air valve stem bent Replace damaged component Contamination on air valve stem Remove and clean Contamination on trigger bearing screw Remove and clean Contamination on fluid needle shaft Remove and clean Fluid needle packing too tight Loosen packing nut Air leak from fluid needle exit point Seal damaged or missing Replace in top of handle Air cap retaining ring will not rotate Contamination on retaining threads Soak gun head in solvent to soften paint Cut retaining ring off of gun probably Deformed or damaged retaining ring replace retaining ring and baffle Unable to turn fan control knob on Internal O ring swollen or broken Replace O ring top rear of gun Paint contamination on threads Remove and thoroughly clean Unable to get round spray Fluid tip or air baffle incorrectly fitted Remove check components for damage and refit correctly Air baffle chinmey damaged Replace air baffle
9. ssure feed Lubricate or replace Tighten Clean vent hole in cup lid Tighten to 8 Nm 70 Ibf in Remove check mating surfaces and re tighten PAGE 2 MAINTENANCE amp TROUBLESHOOTING PAGE 3 SPRAY FAULTS Condition Correction AAA eee Split spray pattern Excessive bounce back FINISH FAULTS Runs and sags Thin sandy coarse finish drying before it flows out Thick dimpled finish orange peel Too much material coarsely atomised Not enough material or too high atomisation pressure Too much atomisation air pressure Gun too far from surface Improper technique i e arcing amp fanning the gun Too much material flow Material too thin Gun tilted on an angle Gun too far from surface Too much air pressure Improper thinner being used Gun too close to surface Air pressure too low Improper thinner being used Material not properly mixed Surface rough oily dirty MAINTENANCE amp TROUBLESHOOTING Reduce air pressure or increase fluid flow by turning fluid needle adjusting screw counterclockwise or increase fluid pressure on pressure feed container Reduce air pressure Check distance normally 6 8 Move at moderate pace parallel to work surface Adjust gun or reduce fluid pressure Mix properly or apply light coats Hold gun at right angle to work and adapt to proper gun technique Check distance normally 6 8 Reduce air pressure and check spray pattern F
10. to paint build up inside air cap between spraying operations Fluid tip needle leakage Check for damage or blockage Slow fluid leak from fluid tip and Fluid Tip internal seat scored damaged or Replace needle seat worn Fluid needle external profile damaged or Replace worn Contamination on needle or tip mating Thoroughly clean surfaces preventing good seal Incorrect fluid tip for fluid needle fitted to Check tip needle selection chart and fit gun correct item Sluggish needle Lubricate packing Tight packing nut Adjust Major fluid leak or fluid jetting from Contamination on needle or tip mating Remove tip and needle and thoroughly fluid tip and needle seat surfaces preventing good seal clean Incorrect fluid tip for fluid needle fitted to Check tip needle selection chart and fit gun correct item Fluid needle stuck or binding up Remove and clean fluid needle shaft or lubricate needle packing or loosen needle packing MAINTENANCE amp TROUBLESHOOTING PAGE 5 MAINTENANCE amp TROUBLESHOOTING PAGE 6 GUN FAULTS Condition 2 Cuse Correction Paint build up on fluid tip Fluid tip not fitted correctly in gun head Tighten to correct torque Fluid tip needle leakage Check for damage or blockage Paint build up on Air cap Damaged air cap holes Replace with new Air cap Gradual build up of bounce back on gun Thorougly clean head Slow fluid leak from needle packing Fluid needle packing worn or loose Tighten or
11. ully Clean air cap Clean Lubricate see lubrication section or loosen packing nut Soak cap or tip in suitable solvent and wipe clean To clean orifice use a broom straw or toothpick Never use a wire or hard instruments This damages holes and distorts spray pattern Note To determine where material build up is invert cap and test spray If pattern shape stays in same position the condition is caused by material build up on fluid tip If pattern changes with cap movement the condition is in the air cap Too much material Material too thick Loose fluid tip Fluid tip not seated correctly in gun head Gun with cup tipped at excessive angle Obstructed fluid passage or hose Loose or cracked fluid tube in cup or tank Insufficient fluid in cup or pressure tank Too heavy fluid for suction feed Dry or worn packing or loose packing nut Plugged vent on suction feed cup Gun fluid inlet loose or not sealed seated correctly Fluid hose or cup not fitted correctly to gun fluid inlet connector MAINTENANCE amp TROUBLESHOOTING Reduce fluid flow by turning fluid needle adjusting screw clockwise Reduce fluid pressure or increase atomisation pressure Thin Tighten to 17 Nm 150 ibf in Remove tip clean components check cone seating on tip and gun for damage or contamination Do not tip excessively or rotate fluid tube Clean Tighten or replace Fill cup or tank Thin material or change to pre
12. with the material being sprayed and its concentration Explosion Hazard Halogenated Hydrocarbon solvents for Guns with stainless steel fluid passages Incompatible Materials example Methylene Chloride and 1 1 1 may be used with these solvents However Trichloroethane are not chemically Aluminium is widely used in other spray compatible with the aluminium which may application equipment such as material be used in many system components pumps cups and regulators valves etc The chemical reaction caused by these Check all other equipment items before use solvents reacting with aluminium can and make sure they can also be used become violent and lead to an equipment safely with these solvents Read the label explosion or data sheet for the material you intend to spray If in doubt as to whether or not a coating or cleaning or cleaning material is compatible contact your material supplier MAINTENANCE amp TROUBLESHOOTING PAGE 1 MAINTENANCE amp TROUBLESHOOTING PAGE 2 SPRAY FAULTS Improper spray pattern Heavy top or bottom pattern Heavy right or left side pattern Heavy centre pattern Intermittent or fluttering spray fan Gun Improperly adjusted Dirty air cap Fluid tip obstructed Sluggish needle Material build up on air cap partially plugged horn holes centre holes or jets Material build up on fluid tip or partially plugged fluid tip Readjust gun follow instructions caref
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