The Problem: Downward “drooping” movement of the paint film immediately following the application of the top coat resulting in an uneven film appearance.
Causes: Applying too much paint. Painting in cool, humid conditions. The application of paint over a glossy surface preventing the top coat from adequately bonding. Over-thinning the paint. And using an airless sprayer positioned too closely to the surface being painted.
How-to-fix: If the top coat is still wet, brush out and/or re-roll to even out the paint film. If the paint has dried, you will need sand and re-apply a new coat of high-quality paint at the recommended spread rate. Finally, avoid unfavorable conditions e.g. painting in cool or humid climates, and sand glossy surfaces.