Pickling

Description

Swelling or wrinkling of the paint surface, varying in severity and most often occurring around feathered edges. The underlying paint may break through the topcoat.

Cause

Reaction of the underlying surface with the applied paint. Often caused by applying 2-pack paints over 1K synthetic paints. 

Prevention

Ensure compatibility of materials or that the underlying layer is thoroughly sealed.

Rectification

Rub down the affected area, taking care not to uncover any areas which could give rise to the same problem, seal the surface and repaint. In severe cases rub down the affected area to the substrate and repaint.