This condition is known as edge mapping. The paint has raised areas that look like the edges of a map. It can be repaired by sanding and refinishing your car or the impacted area.

In this article, I’ll answer common questions about how to prevent edge mapping and eliminate it when it happens.

• What is edge mapping?
• What causes edge mapping?
• How can I repair a surface showing signs of edge mapping?
• How do I prevent edge mapping?

What is edge mapping?

Edge mapping typically looks like the lines on a map. It describes the appearance of uneven edges in your car paint…

What causes edge mapping?

Edge mapping is caused when solvent from a new topcoat penetrates a solvent-sensitive substrate. This causes the lifting or wrinkling that creates the outlines or raised areas…

How can I repair a surface showing signs of edge mapping?

There are three ways to correct this:

1. Sand to smooth or remove the affected area. (Fine sand, using a 400 or finer grit sandpaper.) Isolate the affected area with a two-component primer surfacer and refinish
2. Apply a water-borne primer surfacer, sand smooth, and refinish.
3. Apply an acrylic lacquer primer surfacer thinned with a non-penetrating thinner, sand smooth, and refinish. Gleam has a range of thinners for all situations. Check them out!

How do I prevent edge mapping?

Check questionable finishes by rubbing a small inconspicuous area with a shop towel saturated with lacquer thinner. Finishes susceptible to edge mapping will soften, wrinkle, or shrivel as the lacquer thinner is applied. If any of these reactions occur, you should:

• Use an acrylic urethane primer surface, water-borne primer surface, or acrylic lacquer primer surfacer thinned with a non-penetrating thinner over sensitive substrates.
• Use a 400 or finer grit sandpaper when feather edging.
• Avoid sanding through an insoluble topcoat or clear coat because it will expose solvent-sensitive or soluble finishes.

Prevent edge matching on your automotive surfaces so you always achieve a smooth, professional finish and avoid having to take corrective action.