Solvent Popping

Description

Open topped blisters up to 1 mm in diameter on the surface of the most recently applied paint film.

Cause

Air or solvent vapour trapped by fast drying paint forming a skin.

This may be due to:

1. Poor quality or too fast thinner.
2. Excessive film thickness, or insufficient drying time between coats.
3. Compressed air pressure too low.
4. Drying temperature too high, heat source too close to the film, too hot, or applied too soon.

Prevention

1. Ensure that the surface is scrupulously clean.
2. Use only recommended thinner.
3. Apply paint in thin, wet films. Allow sufficient drying time between coats.
4. Use correct compressed air pressure.
5. Allow sufficient flash off time before force drying, ensure that the correct drying temperature is not exceeded.
6. Do not allow the heat source to be placed too close to the surface.

Rectification

Rub down to a smooth surface and repaint.