Blistering

Description

Blisters appear as swellings on the surface of the paint and vary considerably in both size and density. Coarse blisters, larger than 1.5 mm in diameter, generally occur in patches, although they may also be found in isolation. Fine blisters, typically from 0.5 mm rings, meandering lines or in the shape of a finger print. Blisters in the colour coat are generally more prominent than those occurring between paint and sub-strate.

Cause

Absorption of pigment from the underlying paint, dissolved by the solvents of the new coat.

Prevention

1. Test the original finish by spraying a small, flatted area.
2. Use an approved bleeding inhibitor sealant.
3. Remove any overspray from the surface before painting.

Rectification

Rub down to the original finish, seal with a recommended sealer and repaint.