Diffusion of a soluble dye from the substrate through a paint system. In most cases, bleeding leads to a spot-like discoloration of the topcoat, often producing a reddish or yellowish color shade. Excessive peroxide in a polyester body filler can also cause similar stains due to a chemical reaction with the pigments.
1. Excessive peroxide from a polyester body filler causes a yellow-brownish stain in the topcoat. Blue and green colors are particularly vulnerable to this problem
2. Soluble dyes from the old paintwork are dissolved by the solvent of the repair materials and thus change the color of the surface.
3. Residues from bitumen and tar.
How to avoid
1. Only use the recommended amount of peroxide hardener for the polyester body filler. Mix hardener and body filler thoroughly.
2. Carry out a solvent test. Soluble dyes have not been used in OEM coatings and in any repair materials for many years.
3. Remove all residues from bitumen and tar before painting.
To repair areas damaged by “bleeding”, use suitable isolating products, such as Stone Chip and Underbody Protection or Primer Filler, if applicable. In case of major damages, sand the paint system down to a “sound” surface. Refinish using the recommended undercoats and topcoats.