04
Material
Bleeding / discoloration
Pinkish or reddish patches and discolouration in the finish — migration of pigments or chemical reactions from intermediate coats up through the paint system.
Cause
- Too much hardener mixed into the polyester body filler
- Hardener and body filler not mixed thoroughly — uneven chemical reaction
- Old paint coatings on the body incompatible with the new system
- Filler not sealed with epoxy primer before painting
Prevention
- Follow the mixing ratio — use scales, do not estimate by eye
- Mix the hardener thoroughly into the filler until the consistency and colour are uniform
- Always seal polyester filler with 2K epoxy primer
Repair
- Bleeding cannot be stopped or painted over — the peroxides will keep bleeding through subsequent coats
- The only solution: sand the entire paint system back to bare metal wherever the defect has occurred
- Rebuild the system according to the technology, starting with proper sealing