SPRAY GUN PATTERN
Trouble Shooting
AIR ENTRAPMENT
Small craters in clearcoat.
BLEEDING
Discoloration to topcoat color.
BLISTERING
Small swelled areas appearing like a water blistered
on human skin.
BLUSHING
Finish turns milky or cloudy.
CHECKING
Splits and cracking in surface.
CHIPPING
Small chips or nicks in finish.
DIRT IN FINISH
Foreign particles in paint film.
DULLED FINISH (Dieback)
Loss of gloss as paint drys or ages.
EDGE MAPPING
Raised or lifted edges in the wet or dry paint film
that outline sand through's or featheredge's.
FISHEYES
Small crater like openings during or just after
refinishing.
LIFTING
Existing paint finish wrinkles, shrivels, or swells
during application of new finish.
MOTTLING
Streaking or disorientation of metallic color.
ORANGE PEEL
Paint film having a texture that resembles the skin
of an orange.
PEELING (Delamination)
Paint film loosing adhesion or separating from substrate.
PIN HOLES (Body filler)
Small holes or bubbles located in or on top of putties
or body fillers.
RUNS AND SAGS
Running of wet paint film in rivulets.
SAND SCRATCHES
Lines and markings in paint film resembling sand scratches.
SOLVENT POPPING
Small bubbles, pinholes or crater-like openings in or on the
paint film.
Air Entrapment Top of Page
Small craters in clearcoat.
Cause
Air that is trapped or buried and burst at the surface causing small craters. Lack of atomization is the main cause which is due to the following.
1. Low air pressure
2. Spray gun setup wrong
3. Spray gun to close while spraying
4. Spray gun travel to slow
Repair
Sand cured surface with 1200 grit and finer, then compound and polish or sand out and refinish.
Prevention
Maintain and use the proper:
1. Air pressure
2. Recommended Spray gun setup
3. Spray gun distance
4. Spray gun travel speed
Note: Air entrapment and solvent pop are separate problems. Refer to solvent pop.
Bleeding Top of Page
Discoloration to topcoat color.
Cause
Solvent penetration from fresh color material dissolves old finish, usually found in reds and maroons, releasing a dye from the original finish that come to the surface. Also improper cured filler.
Repair
Once cured apply 2k undercoat to isolate problem then refinish.
Prevention
Use 2k undercoat(s) on suspected colors and then refinish. Staining for body filler, make sure correct mix and not using out dated hardner that isn't older than 18 months, then under coat with 2k product.
Blistering Top of Page
Small swelled areas appearing like a water blistered on human skin
Cause
1. Moisture from air lines, high humidity, or water not dry from wetsanding filler or undercoats
2. Painting over rust, grease, or oil.
3. Trapped solvents
Repair
Sand away affected blisters then refinish
Prevention
1.Make sure air lines are properly fitted with moisture traps and filters and drained on regular basis.
2. Properly prep and clean substrate using recommended products and procedures.
3 Use recommended reducers for spray conditions.
4. Allow proper flash for undercoats and fully dry after wetsanding.
Blushing Top of Page
Finish turns milky or cloudy
Cause
Fast thinner/ reducer used in very humid conditions, or surface is exposed to cold and condensation.
Repair
Apply heat to refinished area, and/or compound and polish once cured. If blushing still appears then sand and refinish.
Prevention
1. Keep surface warm during refinishing in cold temps.
2. Use quality grade thinner/reducers.
3. Use recommended retarders during humid conditions.
Checking Top of Page
Splits and cracking in surface.
Cause
1. Insufficient dry times.
2. Excessive film build of undercoats and topcoats.
3. Recoating over previous checked surface.
4. Incorrect mix ratio's or mixing and/or to much hardener.
5. Extreme temperature changes.
6. Improper thinner/reducer
Repair
Sand and remove, then refinish.
Prevention
1. Follow recommended dry times between coats.
2. Avoid excess film build.
3. Completely remove all cracked finishes before undercoating and refinishing.
4. Stir and mix thoroughly and mix accordingly to manufacturers recommendations.
5. Avoid extreme temperature changes.
6. Use proper thinner/reducers and hardeners for spray application.
Chipping Top of Page
Small chips or nicks in finish
Cause
Impacts of stones or other objects due to the lack of adhesion of refinished paint.
Repair
Sand and remove all imperfections and then refinish.
Prevention
1. Use premium 2k undercoats and topcoats.
2. Follow recommended film thickness.
3. Use flex/flow additives in areas more prone to chipping.
Dirt in Finish Top of Page
Foreign particles in paint film
Cause
1. Foreign objects airborne around working conditions
2. Improper cleaning, blowing off, and tacking of surface before and during refinishing.
3. Dirty spray gun.
4. Work clothes containing dust, lint, and fibers.
Repair
Sand out foreign objects with 1200 grit or finer and then compound and polish or sand and refinish if necessary.
Prevention
1. Maintain spraying area free and clear of dirt.
2. Clean then blowout all areas, then use tack rack before and during refinishing.
3. Properly maintain and clean spray equipment.
4. Use clean and suitable clothes during refinishing.
Dulled Finish (Dieback) Top of Page
Loss of gloss as paint drys or ages.
Cause
1. Use of poor grade material and/or to fast of thinner/reducers for spraying conditions
2. Topcoats applied to wet undercoats.
3. Inadequate flash times between coats
4. Insufficient film thickness (applied to heavy or not enough).
5. Cleaning with caustic cleaners
6. Compounding before finish has cured.
7. Use of poor grade polishes.
8. Aging of finish.
Repair
Allow finish to fully cure than compound and polish with quality products, or sand and refinish.
Prevention
1. Use top quality products and recommended thinners/reducers for spraying conditions.
2. Allow proper dry times of all coatings.
3. Follow recommended film thickness of products.
4. Clean surface thoroughly before painting.
5. Follow recommended times for compounding and polishing and using top quality polishes.
Edge Mapping Top of Page
Raised or lifted edges in the wet or dry paint film that outline sand through's or featheredge's.
Cause
Solvent from new topcoat being applied penetrates sensitive substrate causing lifting or wrinkling that outlines feathered edges.
Repair
Sand and remove affected areas then apply a 2k undercoat or waterbourne primer, then refinish.
Prevention
1. Use 2k acrylic urethane primer/surfacer or waterbourne primer over questionable areas.
2. Use 400 grit or finer sandpaper when featheredging areas.
3. Avoid sanding through fresh or sensitive solvent finishes.
Fisheyes Top of Page
Small crater like openings during or just after refinishing.
Cause
Spraying over surfaces not properly cleaned and contain silicone, grease, oil, or fisheye eliminator
Repair
1. Remove wet paint film with solvent, clean thoroughly and refinish.
2. Add the recommended amount of fisheye eliminator and respray the affected area.
3. If fisheyes appear in a basecoat, allow the color to flash then spray a mist coat over affected area. Do not use fisheye eliminator in undercoats or basecoat color.
4. If the paint has dried, sand affected areas to a smooth finish below the fisheye cratering and refinish.
Prevention
1. Clean surface with waterbased and solvent based cleaners.
2. Use of fisheye eliminator if needed.
3. Maintain and check all spray equipment, air lines, filters and compressor.
Lifting Top of Page
Existing paint finish wrinkles, shrivels, or swells during application of new finish.
Cause
Solvents in newly applied products attacking the previous finish usually due to
1. Insufficient curing of previous finish.
2. Exceeding maximum flash or recoat times during application.
3. Insufficient film build of previous clearcoat.
Repair
Sand and remove problem areas, then refinish.
Prevention
1. Allow previous finishes to cure thoroughly before refinishing.
2. Do not exceed products maximum recoat time during application.
3. Avoid applying under undercoats and topcoats excessively wet.
4. Questionable surfaces prone to lifting, use waterbourne undercoats.
Mottling Top of Page
Streaking or disorientation of color.
Cause
Found in metallic colors due to:
1. Improper spray technique.
2. Uneven film build and tilting of spray gun.
3. Unbalanced spray pattern.
4. Over thinned/reduced basecoat.
5. Clearcoating over basecoat
Repair
Once basecoat has flashed use uniform spray pattern and/or apply a low pressure mist coat.
Prevention
1. Use recommended spray gun setup.
2. Avoid excessive film build or wetting.
3. Use the correct ratio of thinner/reducer
Orange Peel Top of Page
Paint film having a texture that resembles the skin of an orange.
Cause
1. Under reduction and/or air pressure to low.
2. Wrong temperature thinner/reducer for spraying conditions.
3. Excessive film thickness and/or heavy coats.
4. Improper gun setup or spraying technique.
Repair
Sand with 1200 grit or finer, then compound and polish, or sand smooth then refinish.
Prevention
1. Follow recommendations for proper reduction and air pressure.
2. Select recommended temperature reducer for spraying application.
3. Avoid heavy coats.
4. Adjust gun setup and spraying technique.
Peeling (Delamination) Top of Page
Paint film loosing adhesion or separating from substrate.
Cause
1. Improper surface preparation.
2. Incompatible products for application.
3. Insufficient flash/dry time or exceding products maximum recoat time.
4. Insufficient film build of undercoats and/or topcoats
5. Clearcoat finishes:
A. Insufficient film thickness of clearcoat.
B. Solvent cleaning basecoat before clearcoating,
C. Sanding basecoat before applying additional basecoat or clearcoat.
D. Basecoat applied too dry.
E. Clearcoat applied too dry.
F. Baking basecoat before applying clearcoat.
G. Using fisheye eliminator in basecoat.
H. Incompatible clearcoat.
I. Use of incompatible "adhesion promoter".
J. Excessive basecoat film thickness.
K. Over reduction, under reduction, or incompatible reducer used in basecoat.
Repair
Remove peeling paint completely and refinish with compatible materials
Prevention
1. Thoroughly prep and clean all substrates.
2. Use recommended compatible products for application.
3. Do not exceed recommended flash/dry times for recoating.
4. Use of adhesion promoter when recommended.
Pin Holes (Body Filler) Top of Page
Small holes or bubbles located in or on top of putties or body fillers.
Cause
1. Excessive recommended amount of hardener.
2. Applying heavy thick coats produces excessive heat, causing gas bubbles to form inside the product as it cures.
3. Over stirring or whipping motion while mixing.
Repair
Apply polyester glazing putty to fill, sand, then proceed on.
Prevention
1. Use recommended ratio amount of hardener.
2. Apply filler in thinner coats.
3. Mix putty/filler components by folding together and pressing down to eliminate air pockets.
Runs and Sags Top of Page
Running of wet paint film in rivulets.
Cause
1. Over reduction and/or low air pressure.
2. To slow of thinner/reducer for spraying conditions
3. Painting on Cold surfaces
4. Not adhering to proper flash times between coats.
5. Applying excessive wet coats due to:
A. Holding the gun too close to the surface.
B. Slow gun speed.
C. Double coating.
Repair
Remove fresh paint with solvent and then refinish. Once dry sand with 1200 grit or finer than compound and polish or sand smooth then refinish.
Prevention
1. Mix paint, use correct thinners/reducers and adjust air and gun setup to product recommendations.
2. Make sure paint and surface are at room temperature.
3. Spray lighter coats with sufficient flash/dry times between coats.
Sand Scratches Top of Page
Lines and markings in paint film resembling sand scratches.
Cause
1. Sanding with to coarse grit sandpaper during the repair and rinishing.
2. Insufficient dry times of undercoat to fully shrink.
3. To fast of reducers used causing surface to bridge over.
Repair
Once cured, sand and refinish.
Prevention
1. Use recommended grit sandpaper during the repair process.
2. Allow undercoats to fully dry before sanding and topcoating.
3. Use product recommended temperature thinner/reducer for spraying conditions.
Solvent Popping Top of Page
Small bubbles, pinholes or crater-like openings in or on the paint film.
Cause
Liquid solvent thinners/reducers becomes trapped in the paint film when the surface layer skins over too quickly, preventing their evaporation into the atmosphere. Solvents that vaporize within the paint film leave bubbles, pinholes or craters as they push through and pop the surface. Solvents can be trapped due to:
A. Thinner/reducer evaporating too fast for spraying conditions.
B. Inadequate flash time between coats.
C. Excessive film thickness or "piling on" of heavy/wet coats.
D. Too much air movement causing surface to skin over before solvents evaporate.
E. Excessive purge/flash time before force drying.
Repair
Once cured sand with 1200 grit or finer, then compound and polish. Or sand and refinish.
Prevention
1. Use recommended temperature thinner/reducer for spray conditions.
2. Allow proper flash/dry times between coats.
3. Avoid excessive heavy coats.
4. Avoid extended purge/flash time before force drying.
Spray Gun Pattern Trouble Shooting Top of Page
One-sided round fan pattern
Cause
The center air opening on the air cap or fluid tip is clogged or deformed.
Cure
Tear gun down and clean components thoroughly or replace nozzle set if necessary.
One-sided curved fan pattern
Cause
One side of the passage of the air cap horn is clogged or deformed.
Cure
Tear gun down and clean components thoroughly or replace nozzle set if necessary.
Heavy ended fan pattern
Cause
Clogged or deformed air cap horns.
Cure
Clean air cap thoroughly or replace nozzle set if necessary.
Split swallow tail fan pattern
Cause
Material too thin; Air pressure too high; Spray fan pattern adjusted too wide.
Cure
Reduce material accordantly to manufacturers recommendations
Reduce air pressure
Reduce spray fan pattern
Material in center of fan pattern too heavy
Cause
Atomization pressure too low ; Viscosity too high; Too much material applied
Cure
Raise pressure
Thin material to manufactures product recommendations
Use smaller nozzle size
Sporadic or fluttering fan pattern
Cause
Fluid tip or needle not tight; Cup cap vent clogged
Cure
Retighten spray gun parts part
Clean cup cap vent hole