Swelling and lifting of lower paint layers when new paint is applied. Problem may occur during painting or drying.
Causes
1. Flash-off time too long when working wet on wet with 2K products (gel phase)
2. Recoating of solvent-sensitive layers (NC/TPA) with the wrong repair materials or with excessive film builds
3. Film thickness of sealing coats too low (applied too thin or sanded down too far)
4. Substrate layers not thoroughly drie
How to avoid
1. Always keep to recommended flash-off times.
2. Carry out a solvent test and select a suitable paint system.
3. Keep to recommended film builds.
4. Re-dry the substrate, if necessary (e.g., with IR lamps)
Repair
Sand down the paint system to a “sound” surface. Refinish using the recommended undercoats and topcoats.