K.C. Body Shop Supply

Call Us (773) 306-2805

How to: Prevent Bleeding (Discoloration) When Painting Vehicles

How can I prevent paint from bleeding on the surface of my car?

The topcoat has dried, but there is a red, shadowy-like hue “bleeding” through the finish. Depending on the severity of the bleeding, you may be able to apply a sealer undercoat and refinish, or, in extreme cases, remove the paint and refinish.

This article will answer common questions about how to prevent paint bleeding and explain everything you need to know to fix the surface when bleeding begins to happen.

  • What is bleeding?
  • What causes paint bleeding?
  • How can I prevent bleeding?
  • How can I repair a surface that is bleeding?

What causes bleeding on the painted surface of my auto?

Sometimes a soluble dye diffuses and spreads upwards into the topcoat of paint, creating a discoloration, with a reddish or yellowish tint to the finish.

What causes this “bleeding” effect?

Solvents in the top coat paint can react to pigments in the substrate, causing discoloration.

Excessive peroxide in a polyester body filler can cause a chemical reaction with pigments in the paint.

How can I repair a surface showing signs of bleeding?

There are two plans of attack available to correct the problem. (Before you proceed with either approach, be sure you allow enough time for the topcoat to cure completely).

For minimal bleeding:

  • Apply a sealer undercoat.
  • Refinish.

For severe bleeding:

  • Remove the original paint film.
  • Refinish with an undercoat sealer.
  • Apply new topcoat.

How do I prevent bleeding?

Select an appropriate sealer. The sealer will act as a barrier blocking the pigment dye in the substrate from diffusing upward. Gleam Automotive Finish has some of the best sealers available today. You owe it to yourself to try them out.

Apply the sealer according to product recommendations, allowing time for it to dry properly.

Follow the sealer application with a second application of the topcoat paint.

Following these steps will help you prevent bleeding from happening on an otherwise perfect finish.