Coatings Cafe
Clearcoat Yellowing
Defect Description
The clearcoat shows a yellow color especially when compared to an adjacent panel.
The clearcoat can develop yellow color from external contamination such as in black iron or rusted application system pipes. Some clearcoats can develop a yellow color when the bake temperature is outside the process window. The yellowing defect will often appear to be worse with increasing film thickness.
Also known as: yellowing, poor clearcoat color harmony
Possible Causes of Defect
1. Clearcoat contaminated with metal -like iron
2. Paint has not been mixed properly
3. Baking temperatures are too high
4. Film thickness is too high
Tips to Avoid Defect
-
1. Use best practices for selection of clearcoat system piping
2. Mix paints before use, even clearcoats
3. Follow the bake window guidelines
4. Follow the film thickness guidelines
How to Repair the Defect?
- Consult your specific paint shop procedures.
- Finesse Deck: Sand plus 2-step Polish
- Spot Repair: Sand plus Repaint