AIR ENTRAPMENT
Craters
Small crater like openings in or on the paint film.
CAUSE
Trapped or buried air pockets in the wet paint film that rise to the surface and "burst" causing small craters. Lack of atomization is the cause of air entrapment and may be due to one or more of the following:
Spray gun travel too slow.
Spray gun distance to close.
Air pressure to low.
Improper spray gun setup.
REPAIR
Sand with 1200 or finer grit sand paper, 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.
Note: Some cases of air entrapment may have an appearance very similar to solvent pop or dust contamination. However, air entrapment normally occurs when the film is still wet and can be removed with compounding procedures. On the other hand, solvent pop will appear after the film is "skinned over" and when sanded will have pinholes. Dust contamination will appear while the film is drying but, still "tacky". These craters, under close examination, will have a speck of dirt in the center of the crater.
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