Diffusion of a soluble dye from the substrate through a paint system. In most cases, bleeding leads to a spot-like discolouration of the topcoat, often producing a reddish or yellowish colour shade. Excessive peroxide in a polyester body filler can also cause similar stains due to a chemical reaction with the pigments.
- Excessive peroxide from a polyester body filler causes a yellow-brownish stain in the topcoat. Blue and green colours are particularly vulnerable to this problem
- Soluble dyes from the old paintwork are dissolved by the solvent of the repair materials, changing the colour of the surface.
- Residues from bitumen and tar.
HOW TO AVOID
- Only use the recommended amount of peroxide hardener for the polyester body filler. Mix hardener and body filler thoroughly.
- Carry out a solvent test. Soluble dyes have not been used in OEM coatings or any Glasurit repair materials for many years.
- Remove all residues from bitumen and tar before painting.
To repair areas damaged by bleeding, use suitable isolating products, such as Glasurit 1109-1240/4 Stone Chip and Underbody Protection or Glasurit 801-72 VOC EP Primer Filler, if applicable. Where there is major damage, sand the paint system down to a sound surface. Refinish using the recommended undercoats and topcoats.