Description of problem:
The sanding marks underneath the topcoat show through.
Causes:
- Ground coat is too thick.
- Insufficient drying time before the application of the topcoat.
- Sand paper used is too coarse.
- Substrates are soft, not dried enough or sensitive to the solvents present in the topcoat.
- Too low film build.
Preventive measures:
- Do not spray thick substrates. They may be dry on the surface but still soft on the inside.
- Leave enough flash off time between coats.
- Use correct sandpaper grade.
- Use solvent test to identify soft substrates (i.e. T.P.A).
- Apply normal film thickness of the topcoat.
Remedy:
Depending on the seriousness of the problem, either sand lightly with P1200, use rubbing compound and polish, or leave to dry completely, sand and repaint.
.jpg)
© 2024HyMax
