Learn More About Auto Paint Repair Reactions -And How To Understand Them
The Problem Conditions, Causes, Preventions and Solutions.
If auto painting is a new venture for you, it is imperative that you understand the basics of do-it-yourself auto body paint repair.
On this page you will find a treatment of the most common paint finish problems. This format details the condition of the problem, it's causes, prevention and the best solution.
So don't worry, we all see these problems sometimes and in my book a "Professional" is not a person who doesn't make mistakes but a person that can correct the mistake that he has made. By you learning these reactions in automotive painting you'll soon understand what it takes to get PRO finishes all the time!
We always heartily recommend anybody to spend an adequate amount of time preparing their vehicle's surface for paint and therefore minimize the need for car paint repair afterwards.
Too many times, enthusiastic rookie painters get ahead of themselves. They believe that a thick coat of paint will hide blemishes or flaws, it simply won't. Don't rush into things.
Here our list of common paint problems, we'll expand on each topic in detail below:
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Bleeding - Original finish discoloring or color seeping through to the new topcoat color. |
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Blistering - Bubbles or pimples appearing in the topcoat film, often months after application. |
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Blushing - A milky white haze that appears on lacquer films. |
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Chalking - Finish formation caused by pigment powder no longer held by binder, making a dull finish. |
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Chemical Staining - Spotty discoloration of the surface. |
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Chipping - Small chips of a finish losing adhesion to the underlying layer (substrate). |
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Cracking - A series of deep cracks running in no definite pattern. |
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Crazing - Fine splits or small cracks that completely checker an area in an irregular manner. |
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Die Back - Loss of gloss after application. |
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Dirt - Small bumps deposited in, on, or under the paint film. |
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Dry Spray - A rough, textured surface often confined to a small area. |
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Featheredge Splitting - Appears as stretch marks (or cracking) along the featheredge. Occurs during/shortly after topcoat is applied over lacquer primer. |
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Fish Eyes - Tiny surface finish blemishes that resemble small circles of popped paint bubbles, of fish eye appearance. |
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Gloss/DOI - Poor Gloss Finish. |
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Lifting - Surface distortion or shriveling, while the topcoat is being applied or while drying. |
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Line Checking - A series of parallel lines or cracks ranging from very short up to about 18 inches. |
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Micro-Checking - Severe dulling of the film containing many minute cracks that do not touch. |
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Mottling - Only in metallics when the flakes float together to form a spotty or striped appearance. |
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Orange Peel - Uneven Surface Formation - with an orange peel texture. |
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Overspray - Paint materials from another unit falling on adjacent surfaces. |
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Paint Color Matching - Finished panels that don't match the color of standard panels. |
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Paint Runs and Sags - Heavy application of sprayed material failing to adhere uniformly to the surface. |
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Peeling Paint - Loss of adhesion between paint and substrate. |
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Pinholing - Tiny holes or groups of holes in the finish or in putty or body filler. |
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Sand Scratches - Sanding pattern imperfections that show through the finished paint film. |
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Sandscratch Swelling - Enlarged sand scratches caused by swelling action of topcoat solvents. |
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Soft Paint - Easy to damage or penetrate paint film with fingernail. |
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Solvent Popping - Blisters on the paint surface caused by trapped solvents in the topcoats or primer. |
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Water Spotting - General dulling of gloss in spots or masses of spots. |
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Wet Spots - Discoloration and/or the slow drying of various areas. |
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Wrinkling - Surface distortions/shriveling that occurs while enamel topcoat is being applied (or later during the drying stage.) |
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Condition : Original finish discoloring or color seeping through the new topcoat color. Causes
Prevention
Solution : Apply two medium coats of Bleeder seal in accordance with label instructions. Then reapply color coat. |
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Condition : Bubbles or pimples appearing in the topcoat film, often months after application. Causes
Tiny specks of dirt left on the surface can act as a sponge and hold moisture. When the finish is exposed to the sun (or abrupt changes in atmospheric pressure), moisture expands and builds up pressure. If the pressure is great enough, blisters form.
Use of a fast-dry thinner or reducer, especially when the material is sprayed too dry or at an excessive pressure. Air or moisture can be trapped in the film.
Insufficient drying time between coats or too heavy application of the undercoats may trap solvents which escape later and blister the color coat.
Oil, water or dirt in lines. Prevention
Solution : If damage is extensive and severe, paint must be removed down to undercoat or metal, depending on the depth of blisters. Then refinish. In less severe cases, blisters may be sanded out, resurfaced and re-topcoated. |
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Condition : A milky white haze that appears on lacquer films. Causes
Prevention
Solution : Add retarder to the thinned color and apply additional coats. |
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Condition : Formation on the finish caused by pigment powder no longer held by the binder, which makes the finish look dull. Causes (other than normal exposure)
Prevention
Solution : Remove surface in affected area by sanding. Then clean and refinish. Get Over 50 HOURS Of Step-by-Step Video 'inside' The Members Area Here. |
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Condition : Spotty discoloration of the surface. Causes
Prevention
Solution : After washing with detergent and water, rub affected area with rubbing compound and polish. In severe cases, sand to prime and refinish. |
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Condition : Small chips of a finish losing adhesion to the underlying layer (substrate) usually caused by impact of stones or hard objects. |
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Cracking (Line Checking, Micro-Checking) Condition : A series of deep cracks resembling mud cracks in a dry pond and in no definite pattern, they are usually through the color coat and sometimes the undercoat as well. Causes
Prevention
Solution : The affected areas must be sanded to a smooth finish or in extreme cases removed down to the bare metal and refinished. |
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Condition : Fine splits or small cracks often called 'crowsfeet' that completely checker an area in an irregular manner. Causes
Prevention
Solution : There are two ways to overcome crazing:
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Condition : Loss of gloss after application. Cause : Improper evaporation of solvent or poor initial cure. Suggested Corrective Action Checklist
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Condition : Small bumps deposited in, on, or under the paint film. Cause : Foreign particles entering the wet paint film. Suggested Corrective Action Checklist
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Condition : A rough, textured surface often confined to a small area. Cause : Paint that lacks the ability to flow properly. Suggested Corrective Action Checklist
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Condition : Appears as stretch marks (or cracking) along the featheredge. Occurs during or shortly after the topcoat is applied over lacquer primer. Causes
Prevention
Solution : Remove finish from the affected areas and refinish. |
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Condition : Tiny surface finish blemishes that resemble small circles of popped paint bubbles, which seem to occur almost as soon as paint hits an auto body surface. Causes
Many waxes and polishes contain silicone, the most common cause of fish eyes. Small traces of silicone do not allow paint to settle evenly; rather they cause material to encircle the speck of silicone and form a fish's eye. Silicone adheres firmly to the paint film and requires extra effort for its removal. Even small quantities in sanding dust, rags or from cars being polished nearby can cause this failure. - Check for possible contamination in paint materials.
Prevention
Solution
: After affected coat has set up, apply another double coat of
color containing the recommended amount of Fish Eye Eliminator. In severe cases, affected
areas should be sanded down and refinished. |
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Description : DOI is the sharpness by which images are reflected in the surface of a top coat finish. The images are usually evaluated for 90-degree angle. Gloss measures the amount of light reflected from a paint surface read at 20- and 60-degree angles. Cause : Poor DOI is caused by an non-smooth or irregular top coat surface and/or low gloss. Low gloss is caused by an improper topcoat application process or improper solvent selection. Suggested Corrective Action Checklist
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Condition : Surface distortion or shriveling, while the topcoat is being applied or while drying. Causes
Prevention
Solution : Remove finish from affected areas and refinish. |
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Condition : Similar to cracking , except that the lines or cracks are more parallel and range from very short up to about 18 inches. Causes
Prevention
Solution : Remove color coat down to primer and apply new color coat. |
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Condition : Appears as severe dulling of the film, but when examined with a magnifying glass, it contains many small cracks that do not touch. Micro-checking is the beginning of film breakdown and may be an indication that film failures such as cracking or crazing will develop. Solution : Sand off the color coat to remove the cracks, then recoat as required. |
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Condition : Occurs only in metallics when the flakes float together to form a spotty or striped appearance. Causes
- Check solvent selection.
- Check temperature in spray environment (too
cool).
- Check if the imperfection is on the whole
unit or in a specific area. Prevention
Solution : Allow color coat to set up and apply a drier double coat or two single coats, depending upon which topcoat you are applying. |
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Condition : Uneven Surface Formation - much like the physical appearance of orange peel. Results from poor coalescence of atomized paint droplets. Paint droplets dry out before they can flow out and level smoothly together. Causes
- Check for low air pressure.
When the air temperature is too high, droplets lose more solvent and dry out before they can flow and level properly. The ideal temp to paint at is 22.5 degrees centigrade.
Gun fanning before paint droplets have a chance to flow together will cause orange peel.
If the first coats of enamel are allowed to become too dry, the solvent in the paint droplets of following coats will be absorbed into the first coat before proper flow is achieved.
Under-diluted paint or paint thinner with fast evaporating solvents causes the atomized droplets to become too dry before reaching the surface.
Many finishes are formulated with components that aid coalescence. If these are not properly mixed, orange peel will result.
- Check the smoothness of the substrate
surface. Prevention
Solution : Compounding may help with removing orange peel from paint - a mild polishing compound for enamel, rubbing compound for lacquer. In extreme cases, sand down to a smooth surface and refinish, using a slower evaporating solvent at the correct air pressure. "Learn How To Colorsand And Buff Like A PRO For Showroom Gloss" Do You Have what it takes to become a VIP Member? |
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Condition : Paint materials from another unit falling on adjacent surfaces. Cause : Misdirected spray droplets or dry spray. Suggested Corrective Action Checklist
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Condition : Finished panels that don't match the color of standard panels. Cause : Variations in application and/or paint materials. Suggested Corrective Action Checklist
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Condition : Heavy application of sprayed material that fails to adhere uniformly to the surface. Causes
- Check the solvent selection is correct (not
too slow).
- Check for excessive film build up.
- Check the distance of the spray gun from the
surface when spraying. (You should always hold a paint gun at right angles to the surface being
painted from a distance of 6-10 inches.)
- Check for low spray area
temperature. Prevention
Solution : Wash off the affected area and let dry until you can sand affected area to a smooth surface and refinish. |
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Condition : Loss of adhesion between paint and substrate (topcoat to primer and/or old finish, or primer to metal.) Causes
- Check for non-sanding of substrate or primer
application.
- Check for incompatible products.
- Check solvent selection is correct (not too
fast).
Prevention
Solution : Remove finish from an area slightly larger than the affected area and refinish. |
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Condition : Tiny holes or groups of holes in the finish or in putty or body filler, usually the result of trapped solvents, air or moisture. Causes
Prevention
Solution : Sand affected area down to smooth finish and refinish. Access Your Complete Library of VIP Videos Here !Unlimited Downloads, Burn DVD's |
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Condition : Objectionable sanding pattern imperfections that show through the finished paint film. Cause : Imperfections due to soft primer, improper sanding techniques and low top coat film build. Excessive film builds with improper flash times. Suggested Corrective Action Checklist
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Condition : Enlarged sandscratches caused by swelling action of topcoat solvents. Causes
Prevention
Solution : Sand affected area down to smooth surface and apply appropriate sealer before refinishing. |
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Condition : Easy to damage or penetrate paint film with fingernail. Cause : Insufficient cure of paint film. Suggested Corrective Action Checklist
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Condition : Blisters on the paint surface caused by trapped solvents in the topcoats or primer - a situation which is further aggravated by force drying or uneven heating. Causes
- Check other units to determine if a pattern
is beginning to take place.
- Use of fast-dry thinner or reducer,
especially when the material is sprayed too dry or at excessive pressure, can cause solvent popping
by trapping air in the film.
- Insufficient drying time between coats and
too heavy application of the undercoats may trap solvents causing popping of the color coat as they
later escape.
- Check for high temperature in first part of
force dry. Prevention
Solution
: For refinishing solvent popping, if damage is extensive and
severe, paint must be removed down to undercoat or metal, depending on depth of blisters;
then refinish. In less severe cases, sand out, re-surface and re-apply
topcoat. See what others are saying about the VIP Club! |
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Condition : General dulling of gloss in spots or masses of spots. Causes
Prevention
Solution : Compound or polish with rubbing or polishing compound. In severe cases, sand affected areas and refinish. |
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Condition : Discoloration and/or the slow drying of various areas. Causes
Prevention
Solution : Wash or sand affected areas thoroughly and refinish. |
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Condition : Surface distortions (or shriveling) that occurs while enamel topcoat is being applied (or later during the drying stage.) Causes
Prevention
Solution : Remove wrinkled enamel and refinish.
I Thank You for checking out this page and really hope that it has opened your eyes about some of the most common problems faced when getting started with auto body and paint. To gain total DOMINATION and become a very savvy painter and autobody man check out the VIP Membership Club, You'll be glad you did and see why Hundreds of members accross the world are RAVING about the VIP Membership Course. Have access to a private forum and interact with like minded people from all parts of the world. Be cool!
Tony Bandalos |



