FOAMING & CRATERING

Formation of bubbles (foaming) and resulting small, round concave depressions (cratering) when bubbles break in a paint film, during paint application and drying.

POSSIBLE CAUSES:

• Shaking a partially filled can of paint.
• Use of low quality paint or very old latex paints.
• Applying (especially rolling) paint too rapidly.
• Use of a roller cover with wrong nap length.
• Excessive rolling or brushing of the paint.
• Applying a gloss or semigloss paint over a porous surface.

SOLUTION:

• All paints will foam to some degree during application; however, higher quality paints are formulated so the bubbles break while the paint is still wet, allowing for good flow and appearance.
• Avoid excessive rolling or brushing of the paint or using paint that is more than a year old.
• Apply gloss and semigloss paints with a short nap roller, and apply an appropriate sealer or primer before using such paint over a porous surface.
• Problem areas should be sanded before repainting.

Note: Images & information provided by The Rohm & Hass Paint Quality Institute.