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:
- Poor quality or too fast thinner.
- Excessive film thickness, or insufficient drying time between coats.
- Compressed air pressure too low.
- Drying temperature too high, heat source too close to the film, too hot, or applied too soon.
Prevention
- Ensure that the surface is scrupulously clean.
- Use only recommended thinner.
- Apply paint in thin, wet films. Allow sufficient drying time between coats.
- Use correct compressed air pressure.
- Allow sufficient flash off time before force drying, ensure that the correct drying temperature is not exceeded.
- Do not allow the heat source to be placed too close to the surface.
Rectification
Rub down to a smooth surface and repaint.
Other Defects: