Some solutions to common HVLP troubles. Even if you are not trouble-shooting your HVLP sprayer there is a lot of good information here that can help you spray better finishes.
Problem | Cause | Solution |
|---|---|---|
| Orange Peel. | 1. Material drying too fast. | Slower solvent. |
| 2. Gun too far from surface. | Move gun closer to surface. | |
| 3. Material too thick. | Thin material per thinning instructions. | |
| Runs and sags. | 1. Material too thin. | Add material. |
| 2. Moving gun too slow. | 2. Speed up gun movement. | |
| 3. Too much material flow. | Turn material knob counter-clockwise to reduce flow. | |
| 4. Spray gun too close to surface. | Hold gun 8" - 10" from surface. | |
| Pin-holing and solvent pops. | 1. Trapped solvents. | Apply material in lighter coats allowing solvents time to evaporate. |
| 2. Pigment settling. | Possible bad material. | |
| 3. System contamination. | Thoroughly clean all parts. | |
| Fish eyes. | 1. Possible silicone contamination. | Use solvent to clean all parts. |
| Blistering. | 1. Moisture in/on surface. | Dry surface. |
| 2. Incompatible top coats or undercoats. | Make sure coatings are compatible. | |
| Lumpy, coarse surface. | 1. Dirt on surface. | Thoroughly clean surface. |
| Mottled surface finish. | 1. Too much thinner. | Reduce thinner. |
| 2. Poor spray technique. | Follow spraying instructions in the owners manual | |
| No material flow. | 1. Clogged nozzle/air cap. | Disassemble and clean. |
| 2. Clogged cup pressure tube. | Disassemble and clean. | |
| 3. Clogged gun. | Disassemble and clean. | |
| 4. Clogged material hose. | Disassemble and clean. | |
| 5. Poor cup seal. | Inspect seal in cup cap and clean or replace as necessary. | |
| 6. Excess particles in paint. | Strain paint. | |
| Slow material flow. | 1. Material too thick. | Clear material hose of thick material and thin material per thinning instructions. |
| 2. Improper material adjustment. | Turn material adjustment knob until desired flow is achieved. | |
| 4. Poor air flow through filter. | Remove and clean or replace filter. | |
| 5. Excess particles in paint. | Strain paint with filter. | |
| Material leak. | 1.Damage to cup or gun. | Check cup or gun and replace damage parts. |
| 2. Loose packing. | Tighten packing per instructions. | |
| 3. Worn or damaged packing. | Remove and replace. | |
| 4. Worn or damaged cup seal. | Remove and replace. | |
| 5. Loose cup fittings. | Tighten. | |
| 6. Loose nozzle. | Tighten. | |
| 7. Wrong needle/ nozzle assembly. | Refer to material application chart for correct combination. | |
| 8. Damaged needle. | Replace. | |
| 9. Loose material adjuster. | Turn clockwise until needle seals in nozzle. | |
| Pulsating spray. | 1. Check cup seal. | Disassemble and clean. |
| 2. Check packing. | Tighten per instructions. | |
| 3. Loose fitting on cup or gun. | Tighten. | |
| 4. Loose air cap retainer ring. | Tighten. | |
| 5. Loose nozzle. | Tighten. | |
| 6. Damaged air flow ring. | Replace. | |
| 7. Excess particles in paint. | Strain paint. | |
| Excessive overspray. | 1. Material too thin. | Thicken by adding paint. |
| 2. Too much air flow. | Adjust air flow. | |
| 3. Wrong needle/nozzle. | See material chart. | |
| 4. Gun held too far from surface. | Move 8" - 10" from surface. | |
| 5. Wind. | Do not use in windy conditions. | |
| 6. Too much material. | Turn material knob counter-clockwise to reduce flow. | |
| 7. Excess particles in paint. | Strain paint. | |
| Spitting. | 1. Material too thick. | Thin per recommendations. |
| 2. Wrong needle/nozzle. | See material chart. | |
| 3. Coup not sealing. | Tighten or replace seal. | |
| 4. Packing loose. | Tighten or replace seal. | |
| 5. Excessive particles in paint. | Strain paint. | |
| Poor pattern. | 1. Build-up on nozzle. | Clean nozzle and air cap. |
| 2. Wrong needle/nozzle. | Replace. | |
| 3. Clogged air cap. | Clean. | |
| 4. Excessive particles in paint. | Strain paint. | |
| Overheating. | 1. Clogged filter. | Replace. |
| Poor air flow. | 1. Clogged filter. | Replace. |
| 2. Hose kinked. | Move so that kinking does not occur. | |
| 3. Air flow control out of adjustment. | Adjust air flow. | |
| Spray not uniform (spitting). | 1. Material too thick. | Check material viscosity (Thin per instructions). |
| 2. Wrong needle/nozzle assembly. | Change to proper needle/nozzle. | |
| 3. Cup seal leaking. | Tighten cup, replace seal or check valve. | |
| 4. Loose packing. | Adjust or replace packing. | |
| 5. Material not properly mixed, or improperly filtered. | Strain paint. | |
| Poor pattern. | 1. Material buildup on nozzle or air cap. | Clean nozzle and air cap. |
| 2. Worn nozzle/needle. | Replace. | |
| 3. Clogged air cap. | Clean. | |
| 4. Material not properly mixed, improperly filtered. | Strain paint. | |
| Overheating. | 1. Clogged filter. | Replace. |
| Poor air flow. | 1. Clogged filter. | Replace filter. |
| 2. Air flow control improperly adjusted. | Adjust air flow control. | |
| Spray tip clogs. | 1. Improper material flow adjustment. | Adjust material control. |
| 2. Cup seal leaking. | Replace cup seal. | |
| 3. Wrong needle/nozzle. | Change to proper needle/nozzle. | |
| Orange Peel. | 1. Material drying too fast. | Use a slower solvent, or add a retarding agent. |
| 2. Gun too far from surface. | Move gun closer to surface. | |
| 3. Material too thick. | Thin material per thinning instructions. | |
| Runs and sags. | 1. Material too thin. | Add material to increase thickness. |
| 2. Moving gun too slow. | Move gun more quickly. | |
| 3. Excessive material flow. | Turn material control knob clockwise to reduce flow. | |
| 4. Gun too close to surface. | Move gun further from surface. | |
| Pin-holding and solvent pops. | 1. Trapped solvents. | Apply material in lighter coats allowing solvents time to evaporate. |
| 2. Pigment settling. | Possible bad material. | |
| 3. System contamination. | Thoroughly clean all parts. | |
| Fish eye. | 1. Possible silicone contamination. | Use solvent to clean all parts. |
| Blistering. | 2. Moisture in/on surface. | Dry surface. |
| 3. Incompatible top coats or undercoats. | Make sure coatings are compatible. | |
| Lumpy, coarse surface. | 1. Dirt on surface. | Thoroughly clean surface. |
| Mottled surface finish. | 2. Too much thinner. | Reduce thinner. |
| 3. Poor spray technique. | Refer to "Operation" for spraying instructions. | |
| No material flow. | 1. Clogged nozzle/air cap. | Disassemble and clean. |
| 2. Clogged cup pressure tube or fittings. | Disassemble and clean (a straight pin can be used to clean fittings). | |
| 3. Clogged gun. | Disassemble and clean. | |
| 4. Clogged material tube. | Disassemble and clean gun, and check valve. | |
| 5. Cup seal leaking. | Inspect cup seal, cup cap, and clean and replace as necessary. | |
| 6. Material not properly mixed, or improperly filtered. |