Description: A “goose pimple” or volcano-like appearance in paint film which, on close examination, frequently contains small holes at the center of the bumps.
Causes:
- Improper evaporation of solvent from wet paint film during initial cure or force dry
- Improper application of product: product applied to heavily; inadequate flash time between coats
- Incorrect mix ratio/viscosity
- Incorrect hardener/reducer for shop temperature
Corrective Action Checklist:
- Check to determine if defect is on entire unit or in just a specific area
- Check for high temperature in first part of force dry
- Check other units on line to determine if a pattern exists
- Check for correct reducing solvent
- Check whether defect is specific to one or many colors
- Check whether defect is most prevalent on horizontal surfaces
- Check for excessive film builds
- Check for high fluid delivery
- Check for low air pressure
- Check for high viscosity
- Check for too much overlap in film build
- Check for proper flash and purge times
Prevention:
- Allow adequate flash times
- Choose a suitable hardener/reducer for size of repair and booth temperature
- Check viscosity using a #2 Zahn Viscosity Cup
Repair:
- Minor pop can be sanded and buffed
- Severe pop must be thoroughly sanded and repainted
