Wrinkling

A rough, crinkled paint surface occurring when paint forms a "skin".

POSSIBLE CAUSES:
Paint applied too thickly (more likely when using solvent-based paints).

Painting a hot surface or in very hot weather.

Exposure of uncured paint to rain, dew, fog or high humidity levels.

Applying top coat of paint to insufficiently dried first coat.

Applying a paint which uses a stronger solvent, such as chlorinated rubber paint on top of a conventional coating (pickling)

SOLUTION:
Scrape or sand substrate to remove wrinkled coating. Repaint, applying an even coat of top quality exterior paint. In some instances the underying paint could still be soft and will need further time to dry before repainting is undertaken.

Apply paints at the manufacturer's recommended spread rate (two coats at the recommended spread rate are better than one thick coat). When painting during cool or damp weather, allow extra time for the paint to dry completely.