Cause

Trapped or buried air pockets in the wet paint film that rise to the surface and "burst" causing small craters. Lack of atomization may be due to one or more of the following:

• Spray gun travel too slow.
• Spray gun distance too close.
• Air pressure too low.
• Improper spray gun setup.

Repair

Sand with 1200 or finer grit sandpaper, then compound and polish to restore gloss.

Or, sand smooth and refinish.

Prevention

• Maintain correct spray gun speed.
• Maintain correct spray gun distance.
• Use the recommended air pressure.
• Use the correct air cap/nozzle/needle recommended for the clear coats.

Cause

Solvent in the new topcoat dissolves soluble dyes or pigments in the original finish, allowing them to seep into and discolor the new topcoat.

Repair

Allow color to cure, isolate with two component undercoat(s) and refinish.

Or, remove original paint film and refinish.

Prevention

Isolate suspected bleeding finish by applying a two component surfacer and/or sealer. Allow to cure following product recommendations, then apply desired topcoat.

Cause

Moisture trapped beneath the paint film due to:

• Improper dry time after wet sanding.
• Contaminated air lines.
• Spraying in extreme high humidity conditions.
• Using a poor grade and/or too fast evaporating thinner/reducer.
• Trapped solvents from applying wet heavy coats with insufficient flash time.
• Improper dry time of undercoats before topcoating.
• Painting over grease, oil or rust.

Repair

Remove affected area and refinish.

Extreme cases must be stripped to bare substrate before refinishing.

Prevention

• If wet sanding, allow sufficient time for moisture to evaporate. Drain moisture from compressor and air lines regularly. Allow additional flash time between coats in humid conditions.
• Select proper thinner/reducer for spray conditions.
• Apply materials per product recommendations, allowing sufficient flash time between coats.
• Allow undercoats to thoroughly dry/cure before topcoating.
• Clean and prep substrate using recommended products and procedures.

Cause

When spraying in humid conditions, air from the spray gun and solvent evaporation lowers the substrate temperature below the dew point, causing moisture to condense in or on the paint film. Aggravated by too fast drying or unbalanced thinner/reducer.

Repair

Should blushing occur during application:

• Apply heat to the affected area, or
• Add retarder and apply additional coats.

If the finish has dried, minor blushing may be corrected by compounding or polishing. Severe blushing will require sanding and refinishing.

Prevention

• Always use good quality solvent and thin/reduce material according to label directions.
• Select proper thinner/reducer for spray conditions.
• Add the recommended amount of retarder when spraying in humid conditions.
• Apply heat after application to evaporate moisture.

Cause

Pigment is no longer held and protected by resin, resulting in a powder-like surface and lack of gloss due to:

• Natural weathering of the paint film.
• Improper application of paint material.
• Using generic thinner/reducer and/or hardener.
• Excessive use of mist/fog coats when applying single stage metallic finishes.

Repair

Compound to remove oxidation and polish to restore gloss.

Or, sand to remove "weathered" paint film and refinish.

Prevention

• Weekly washing and occasional polishing or waxing will remove oxidation.
• Thoroughly stir, shake or agitate all paint materials.
• Use the recommended thinner/reducer and hardener, and measure accurately.
• When spraying single stage metallic finishes, apply mist/fog coats panel by panel while finish is still wet.

Cause

A chemical change occurs when harmful environmental contaminants — such as acid rain, tree sap, bird droppings, road tar, etc. — remain on the surface for an extended period of time.

Repair

• Wash with soap and hot water, rinse and dry.
• Solvent clean with appropriate surface cleaner.
• Wash with baking soda solution (1 tbsp per 1 qt water) and rinse thoroughly.
• Compound damaged surface and polish to restore gloss.
• If needed, wet sand with 1500–2000 grit, then compound and polish.*
• If refinishing is necessary, sand to remove damaged area, wash with baking soda solution, then refinish.

Prevention

• Remove harmful contaminants by regularly washing with detergent and water.
• Polish or wax periodically.
• Avoid parking under trees or near factories that produce chemical fallout.
• Refinish with an acrylic urethane basecoat/clearcoat system for maximum protection.

Cause

Loss of adhesion of the paint film to the substrate caused by an impact from stones or other hard objects.

Repair

Sand and featheredge damaged areas to remove chips, then refinish.

Prevention

• Use premium two component undercoat and topcoat system.
• Use a flex agent in undercoat and/or topcoat system in areas prone to chipping.

Cause

• Original finish has "drifted" from manufacturer's standard.
• Old finish weathered and oxidized.
• Color over or under reduced.
• Improper spray procedures.
• Color not properly stirred or shaken.
• Improper spray gun setup.
• Inaccurate mixing of the color formula.
• "Panel" painting instead of blending.
• Evaluating color under incorrect lighting.
• Adjusting a basecoat before applying clearcoat.

Repair

If color is close enough to blend:

• Prepare adjacent panel(s) for blending, then blend color into adjacent panels.

If color must be tinted:

• Tint the color for a blendable match.
• Prepare adjacent panel(s) for blending.
• Respray the repair, blending into the adjacent panel(s).

Prevention

• Check alternate color selector for variances.
• View all color under equal gloss; compound or polish the area to be matched.
• Thin/reduce according to label directions.
• Stir or shake materials thoroughly.
• Recheck color code, formula number, formula weights before mixing.
• Spray a test panel prior to application.
• Always use natural daylight or color corrected lights for color matching decisions.
• Basecoats must have clearcoat applied. Check color from all angles, face (90°) and side tone (20–60°).

Cause

• Excessive film thickness of undercoat and/or topcoat.
• Refinishing over a previously crazed/cracked surface.
• Insufficient flash time between coats and/or force drying undercoats using air from the spray gun.
• Mixing incorrectly or using too much hardener.
• Paint ingredients not thoroughly stirred or agitated.
• Breakdown of finish due to prolonged exposure to sunlight, moisture, and extreme temperature changes.
• Using generic reducers and/or hardeners.

Repair

Remove all cracked paint film and refinish.

Prevention

• Apply all materials following label directions.
• Completely remove crazed/cracked finishes before refinishing.
• Do not force dry undercoats by fanning with spray gun air.
• Mix ingredients thoroughly using recommended additives in proper sequence.
• Stir or agitate materials thoroughly before use.
• Use premium two component undercoat and topcoat system.
• Use the recommended thinner/reducer and hardener, and measure accurately.

Cause

• Inadequate cleaning of the surface to be painted.
• Dirty spraying environment.
• Inadequate air filtration.
• Dirty or unsuitable work clothes containing dust, lint, or fibers.
• Particles from deteriorated air supply lines.
• Using poor grade masking paper.
• Dirty spray gun.
• Removing the vehicle from the spray booth before the finish is "dust free".

Repair

• Sand with 1200 or finer grit sandpaper, then compound and polish to restore gloss.
• Or, sand smooth and refinish.

Prevention

• Thoroughly blow off around windows, doors, jambs, hood, trunk, moldings, and wheel openings. Wipe surface and masking paper with a tack rag.
• Maintain a clean working area.
• Install proper air filters. Never use residential furnace filters in spray booth.
• Wear a lint-free paint suit during spray application.
• Use quality masking materials.
• Repair or replace defective air lines.
• Properly clean and maintain spray equipment.
• Keep vehicle in a clean environment until finish is "dust free".

Cause

Solvent from the new topcoat penetrates a solvent-sensitive substrate causing lifting or wrinkling that outlines the featheredge.

Repair

• Sand smooth or remove the affected area (final sand with 400 or finer grit).
• Isolate with two component primer surfacer and refinish.
• Or, apply water borne primer surfacer, sand smooth and refinish.
• Or, apply acrylic lacquer primer surfacer thinned with non-penetrating thinner, sand smooth and refinish.

Prevention

• Check questionable finishes by rubbing a small area with a shop towel saturated with lacquer thinner. If the finish softens, wrinkles or shrivels, consider the following:
• Use acrylic urethane, water borne, or non-penetrating acrylic lacquer primer surfacer over sensitive substrates.
• Use 400 or finer grit sandpaper when featheredging.
• Avoid sanding through insoluble topcoat, exposing solvent-sensitive finishes.

Cause

• Spraying over surfaces contaminated with oil, wax, silicone, grease, etc.
• Use of thinner/reducer in place of a solvent cleaner.
• Spraying over previously repaired areas containing "fisheye eliminator" additive.

Repair

• Remove wet paint film with solvent, clean and refinish.
• Add the recommended fisheye eliminator and respray the affected area.
• If fisheyes appear in a basecoat, allow the color to flash then spray a mist coat. Do not use fisheye eliminator in undercoats or basecoat color.
• If the paint has dried, sand to a smooth finish below the cratering and refinish.

Prevention

• Thoroughly clean the surface with detergent and hot water, followed by the recommended solvent cleaner. Wipe dry with clean rags.
• Use fisheye eliminator specifically recommended for the topcoat.
• Install an air filtering system to remove oil and moisture contamination.
• Maintain air supply by draining, cleaning and changing filters routinely.

Cause

Solvents in a newly applied product attack the previous finish due to:

• Recoating enamels or urethanes that are not fully cured.
• Exceeding maximum flash or recoat times during application.
• Recoating a basecoat/clearcoat finish where existing clearcoat has insufficient film build.

Repair

Remove lifted areas and refinish.

Prevention

• Check questionable finishes with lacquer thinner on a shop towel. If the finish softens, swell or shrivels, take appropriate precautions.
• Do not exceed a product's maximum recoat time.
• Allow enamels or urethanes to thoroughly cure before recoating.
• Avoid applying undercoats or topcoats excessively wet.
• Avoid lacquer products over an air dried enamel finish.
• Apply two component primer surfacer and/or sealer as a barrier between new and old finish.
• Use water borne undercoats to repair extremely sensitive finishes.

Cause

• Topcoat applied in heavy, wet coats.
• Inadequate flash time between coats.
• Insufficient film thickness of topcoat color or clearcoat.
• Insufficient drying/curing of undercoats before topcoating.
• Using a poor grade and/or too fast evaporating thinner/reducer.
• Improper cleaning of the substrate.
• Insufficient air movement during and after application.
• Spraying over deteriorated or solvent-sensitive substrate without proper priming or sealing.
• Natural weathering of the finish.

Repair

Allow finish to cure thoroughly, compound or polish to restore gloss.

Or, sand and refinish.

Prevention

• Apply topcoat per product label directions using recommended gun setup and air pressure.
• Allow all coatings sufficient flash between coats.
• Apply sufficient coats to achieve recommended film thickness.
• Allow undercoats to thoroughly dry/cure before topcoating.
• Select recommended thinner/reducer based on temperature, humidity, and air movement.
• Clean substrate thoroughly before and after sanding.
• Use a premium two component undercoat system for maximum holdout.
• For air dry: allow exhaust fan to run 40+ minutes after spraying; maintain shop temperature of 60°F or above.

Cause

Uneven distribution of metallic flake caused by:

• Spray gun giving an unbalanced spray pattern.
• Tilting the spray gun during application.
• Holding the gun too close to the surface (flooding).
• Uneven spray pattern overlap.
• Omitting or improper use of mist coats.
• Too much thinner/reducer; color over-thinned/reduced.
• Applying clearcoat before basecoat has thoroughly flashed/dried.

Repair

• To uniform single stage metallic finishes, apply a higher pressure mist coat panel by panel while previous coat is still wet.
• Or, allow basecoat color to flash, then apply a low pressure mist coat.
• Finishes that have dried must be sanded and refinished.

Caution: Large areas of basecoat must have clearcoat applied before sanding. Small nibs may be removed from basecoat by wet sanding on the defect only. Apply additional basecoat to the sanded area before clearcoating.

Prevention

• Use recommended spray gun, fluid tip and air cap. Always adjust for best atomization and balanced spray pattern before application.
• Use the correct ratio of thinner/reducer.
• Allow basecoat proper flash/dry time before clearcoating.
• Follow basecoat application procedures.

Cause

• Under reduction and/or air pressure too low.
• Thinner/reducer evaporates too fast for spray conditions.
• Excessive film thickness or piling on of heavy wet coats.
• Improper spray gun setup.
• Improper painting technique.

Repair

• Compound or polish to reduce surface texture.
• Or, sand smooth with 1200 or finer grit sandpaper, compound and polish to restore gloss.
• Or, sand smooth and refinish.

Prevention

• Use proper reduction ratio and spray at recommended air pressure.
• Select recommended thinner/reducer based on temperature, humidity, and air movement.
• Avoid heavy coats and excessive film thickness.
• Use recommended spray gun, fluid tip and air cap. Always adjust for best atomization and balanced spray pattern.
• Hold the gun perpendicular and parallel to the surface. Adjust speed, pattern overlap, and distance to achieve desired appearance.

Cause

• Improper preparation of the substrate.
• Omitting or applying an incompatible undercoat.
• Insufficient flash/dry time or exceeding maximum recoat time.
• Insufficient film thickness of undercoat or topcoat.
• Clearcoat specific issues: insufficient clearcoat thickness, solvent cleaning basecoat before clearcoating, sanding basecoat before applying additional coats, baking basecoat before clearcoating, using fisheye eliminator in basecoat, incompatible products, excessive basecoat film thickness, or improper reducer.

Repair

Remove the finish in the affected area, featheredge, and refinish.

Or, strip to bare substrate and refinish.

Prevention

• Clean and prepare all substrates according to product recommendations.
• Use the recommended undercoat for the substrate being finished. Plastic parts may require special primer and flex additive.
• Recoat all products within their recommended minimum and maximum recoat time.
• Apply sufficient coats to obtain the recommended film thickness.
• Follow basecoat/clearcoat application procedures using only recommended/compatible products.
• "Adhesion promoter" should only be used when specifically recommended.

Cause

Air or gas bubbles become trapped inside putty or filler during mixing or application, exposed during sanding. Air or gas is trapped when:

• Filler and hardener are mixed using a "whipping" motion (fast circular motion).
• Adding too much hardener.
• Applying heavy thick coats that produce excessive heat during curing.

Repair

Apply a thin layer of polyester glazing putty (properly catalyzed and mixed), sand smooth and continue the repair process.

Prevention

• Mix putty/filler components by folding together and pressing down to eliminate air pockets.
• Apply putty/filler in thin coats. Do not exceed manufacturer's recommended total film thickness.
• Follow manufacturer's recommendation for correct ratio of putty/filler to hardener.

Cause

When vehicles are transported by rail, iron dust particles created by friction between train wheels and the track settle on the finish. When exposed to oxygen and moisture, this dust corrodes and becomes embedded in the finish.

Repair

• Use a 30x magnifying glass to verify rail dust damage.
• Wash the vehicle with soap and water, rinse and dry.
• Solvent clean with appropriate surface cleaner.
• Use an acid-based rail dust remover per manufacturer's directions.
• Rinse with cold water and inspect. Repeat if necessary.
• If finish is pitted, sand with 1200 or finer grit, then compound and polish to restore gloss.*
• Or, sand and refinish.

Prevention

Unfortunately, since this type of damage usually occurs during shipment or storage, little can be done to prevent its occurrence.

Cause

• Over reduction and/or too slow evaporating thinner/reducer.
• Applying paint without proper flash time between coats.
• Applying excessive wet coats: gun too close, slow gun speed, or double coating.
• Air pressure too low during spray application.
• Improper spray gun setup or unbalanced spray pattern.
• Material and/or substrate temperature too cold.

Repair

• Remove the wet paint film with solvent, clean and refinish.
• Or, after finish is completely dry, block sand with 1200 or finer grit, compound and polish to restore gloss.
• Or, block sand smooth and refinish.

Prevention

• Mix according to product directions. Select recommended solvent based on temperature, humidity, air movement, and size of repair.
• Spray medium wet coats and allow sufficient flash time between coats.
• Adjust spray gun for best atomization and balanced spray pattern before application.
• Set air pressure at the gun per product recommendations.
• Use recommended spray gun, fluid tip and air cap combination.
• Allow paint material and substrate to reach room temperature before application.

Cause

Scratching or distorting metallic/mica flakes close to the surface of the paint film due to:

• Sanding single stage or basecoat metallic finishes prior to clearcoating.
• Sanding single stage metallic finishes prior to buffing.

Repair

Allow finish to dry, sand and refinish.

Prevention

• Avoid sanding basecoat finishes before clearcoating. If sanding is necessary, apply additional color following label directions.
• When sanding single stage finishes, confine sanding to minor imperfections (nib sanding rather than entire panels).
• For best results use 1200 or finer grit sandpaper.

Cause

• Sanding the substrate with too coarse grit sandpaper.
• Insufficient dry/cure of undercoats before sanding and topcoating.
• Refinishing over soft, soluble substrates.
• Using a poor grade and/or too fast evaporating thinners/reducers causing primer to "bridge" over sand scratches or topcoat to "skin over" trapping solvent.
• Using a solvent cleaner too strong for the substrate or using thinner/reducer as a surface cleaner.

Repair

Allow finish to dry/cure, sand smooth, compound or polish to restore gloss.

Or, sand and refinish.

Prevention

• Sand with recommended grit sandpaper.
• Allow undercoats to thoroughly dry/cure before sanding and topcoating.
• Test old finish with lacquer thinner; if soluble, apply appropriate sealer.
• Select recommended thinner/reducer. Apply primer surfacer in thin wet coats with adequate flash time to avoid "bridging" scratches.*
• Use solvent cleaner designated for either lacquer (soluble) or cured enamel/urethane (insoluble) substrates.

Cause

• Material not properly stirred or agitated.
• Failure to strain material.
• Using material exceeding its shelf life.
• Using generic reducers and/or hardeners.
• Using materials beyond their specified pot life.
• Using contaminated thinner/reducer or hardener.
• Using contaminated water borne products.

Repair

Remove the wet paint film with solvent, clean and refinish.

Or, sand smooth and refinish.

Prevention

• Stir or shake materials thoroughly to be sure all pigment/resin is in solution.
• Strain all undercoats and topcoats.
• Do not use material that cannot be stirred or strained. Note: Repeated straining will not completely remove seediness.
• Use the recommended thinner/reducer and hardener, and measure accurately.
• Mix only enough material that can be used within specified pot life.
• Use material as soon as possible; close container lids immediately after use.
• Do not allow thinner/reducer to contact water borne products.

Cause

• Topcoating before undercoats have thoroughly dried/cured.
• Undercoats applied excessively wet with inadequate flash time.
• Undercoats under reduced.
• Using a poor grade and/or too fast evaporating thinner/reducer.
• Finishing over body filler that has not thoroughly cured.
• Using too strong solvent cleaner or using thinner/reducer as a surface cleaner.

Repair

Allow the affected area to thoroughly dry/cure, sand and refinish.

If additional filling is necessary, apply a primer surfacer, sand smooth and refinish.

Prevention

• Allow undercoats to thoroughly dry/cure before sanding and/or topcoating.
• Thin or reduce undercoats per product label directions. Apply in thin wet coats with adequate flash time.
• Select recommended thinner/reducer based on temperature, humidity, air movement, and size of repair.
• Follow body filler manufacturer's recommended cure time.
• Use solvent cleaner designated for the substrate type.

Cause

• Applying undercoat and/or topcoat excessively wet.
• Insufficient dry time between coats.
• Improper shop ventilation or heating.
• Adding too much or too little hardener.
• Using incorrect thinner/reducer for spray conditions.
• Omission of drier in enamel/urethane topcoats.

Repair

• Allow additional dry time, maintaining shop temperature of 70°F or above.
• Or, force dry following temperature and time recommendations.
• Or, remove soft paint film and refinish.

Prevention

• Use recommended spray gun, fluid tip and air cap. Adjust for best atomization before application.
• Allow sufficient flash time between coats.
• Maintain shop temperature at 70°F or above.
• Use the recommended hardener and measure accurately.
• Select appropriate thinner/reducer based on conditions. Allow additional flash time in extreme temperature or humidity conditions.
• Add the correct amount of drier specifically listed in the color formulation.

Cause

Liquid solvent becomes "trapped" in the paint film when the surface layer skins over too quickly, preventing evaporation. Solvents can be trapped due to:

• Thinner/reducer evaporating too fast for spraying conditions.
• Inadequate flash time between coats.
• Excessive film thickness or piling on of heavy/wet coats.
• Too much air movement causing surface to "skin over" before solvents evaporate.
• Excessive purge/flash time before force drying.

Repair

Allow finish to thoroughly dry/cure, sand smooth and refinish. Inspect carefully to ensure all craters have been removed.

Severe popping will require removal of the affected film. Prime, seal and recoat as necessary.

Prevention

• Select recommended thinner/reducer based on temperature, humidity, air movement and size of repair.
• Allow for proper flash time between coats.
• Avoid "piling on" or double wet coats.
• Restrict air movement over the surface being painted.
• Avoid extended purge/flash time before force drying.

Cause

• Using too much or too little hardener in the putty/filler.
• Insufficient mixing of putty/filler components.
• Applying surfacer, sealer and/or topcoat before putty/filler has thoroughly cured.
• Applying undercoats and/or topcoats excessively wet.
• Clearcoating a white or light color without using stain-free body filler.

Repair

Allow topcoat to thoroughly cure.

Sand affected area, isolate with two component undercoats and refinish.

Prevention

• Use correct amount of body filler hardener.
• Mix components thoroughly.
• Allow putty/filler to cure thoroughly before topcoating.
• Apply undercoats and/or topcoats in medium-wet to wet coats; always allow proper flash time between coats.
• Use non-staining body filler, especially when clearcoating light colors.
• Isolate suspected staining filler with a two-component surfacer and sealer — allow to fully cure for maximum stain resistance.

Cause

Finish not dry before taping, causing solvent entrapment between finish and tape.

Using a non-automotive tape for multi-color finishes — solvents from additional color soak through the tape into the previous color.

Repair

• Compound and polish to remove texture.
• Or, sand with 1500–2000 grit, compound and polish to restore gloss.
• Or, sand and refinish.

Prevention

• Allow the finish to thoroughly dry before masking.
• Use only high quality automotive masking tape.
• Determine if it is safe to tape on freshly painted surfaces by applying a small piece of tape for 10–15 minutes; remove and check for imprinting.
• De-tack the tape before applying by pulling the adhesive side over your pant leg or between your fingers.
• Remove the tape as quickly as possible after applying additional color(s).

Cause

• Color not thoroughly stirred/agitated.
• Color over-thinned/reduced.
• Substrate not uniform in color.
• Wrong color undercoat used.
• Insufficient number of color coats applied.

Repair

Apply additional coats of color until hiding is achieved.

Or, sand and apply similar colored undercoat/ground coat and refinish.

Prevention

• Stir or shake paint material thoroughly, making sure all pigment is in solution/suspension.
• Thin/reduce according to product label directions.
• Use a sealer or ground coat to provide a uniform color before topcoating.
• Use an undercoat that is similar in color to the topcoat.
• Spray until hiding is achieved.

Cause

Allowing water to come into contact with a finish that is not thoroughly dried/cured.

Washing finish in direct sunlight.

Repair

• Wipe with a damp cloth, then polish.
• Or, compound and polish.
• Or, sand smooth with 1500–2000 grit, compound and polish to restore gloss.
• Or, sand and refinish.

Prevention

• Do not allow water to come into contact with newly painted finish.
• If a new finish does get wet, dry immediately with a soft cloth.
• Wash new finishes in the shade and wipe dry.

Cause

• Excessive film thickness or piling on of heavy wet coats.
• Placing a newly painted finish in hot sun too soon after spraying.
• Using lacquer thinner to reduce synthetic enamel.
• Spraying in extreme hot, humid weather conditions.
• Under reduced and/or too fast evaporating thinner/reducer.
• Air pressure too low during spray application.
• Force drying of air-dry enamels without the recommended additives.

Repair

If defects are minor: Sand the top surface smooth, allow to cure and refinish.

If defects are severe: Remove the affected area and refinish.

Prevention

• Avoid excessive film thickness and heavy coats. Always allow sufficient flash times.
• Keep newly painted finish away from direct sunlight until finish has dried/cured.
• Use reducer specifically recommended for the topcoat.
• Use the recommended reducer, additive and/or retarder in hot humid weather.
• Select recommended thinner/reducer based on temperature, humidity, air movement, and size of repair.
• Use the proper reduction ratio and spray at recommended air pressure.
• Select recommended additives to suit drying conditions. Follow force dry temperatures and time recommendations.