Running or sagging of a wet paint film that resembles drips or a curtain of film.
Causes
- Applying too much paint in 1 coat
- Low air pressure
- Too little flash time between coats
- Holding gun too close to the surface and/or moving too slow
- Surface and/or spray conditions are too cold
- Using too slow of a reducer and/or hardener
Prevention
- Allow sufficient flash times between coats
- Choose the proper reducer for the spray temperature and hardener as recommended per the product data sheet
- Adjust air pressure and fluid control per product data sheet or spray gun chart
- Allow substrate and spray booth to reach proper spray temperature before refinishing
Correcting
- Use solvent to remove the sag and then refinish
- Allow paint to fully cure and then sand the run/sag smooth before polishing
