How can I get rid of odd-shaped pitting
or discoloration on my car paint?

Chemical stains or etching are common car finish issues. Minor cases can be eliminated by cleaning with soap and water or a solvent cleaner. Severe cases may require removing the finish from the damaged area and applying a new one.

In this article, I’ll answer common questions about preventing chemical staining and etching and how to eliminate it when it happens.

• What is chemical staining/etching?
• What causes chemical staining/etching?
• How can I prevent chemical staining/etching?
• How can I repair the surface when I notice chemical staining/etching?
  
  

What is chemical staining/etching?

Spotty discoloration or irregular pitting on a finish are clear signs of chemical staining/etching.

What causes chemical staining/etching?

Embedded contaminants, from nature and the environment, can wreak havoc on even the best paint surface. Whether it is bird droppings, tree sap, acid rain, or even regular water droplets (mineral-laden), contaminants remaining on a paint surface for an extended period can result in a chemical reaction on the finish, burning through a clear coat, resulting in staining or etching.

How do I prevent chemical staining/etching?

Chemical staining/etching of any paint finish can be prevented by following these four suggestions:

1. Remove contaminants by regularly washing your vehicle with water.
2. Polish or wax your car periodically.
3. Avoid parking under trees or near factories that release chemicals into the atmosphere.
4.  Refinish your vehicle with an acrylic urethane system for maximum protection.
   
   

How can I repair a surface that has chemical staining/etching?

Here are four possible solutions:

1. Wash the vehicle with soap and hot water, rinse, and dry.
2. Solvent clean with appropriate surface cleaner.
3. Wash with baking soda solution and rinse thoroughly. (One tablespoon of baking soda per one quart of water.)
4. Compound the damaged surface and polish to restore gloss.
   • If polishing does not remove the damage, wet sand with 1500-2000 grit sandpaper, then compound and polish to restore gloss.
   • If refinishing is necessary, sand to remove the damaged area with appropriate grit sandpaper, wash with a baking soda solution, then refinish. In severe cases, the finish must be removed to bare metal.
     
     

Two additional considerations when repairing chemical staining/etching:

1. When sanding and buffing a basecoat or clear coat finish, always maintain a minimum film thickness of 2.5 mils of clearcoat to provide adequate ultraviolet protection.
2. Refinishing is recommended if correcting the damage involves removing more than 0.5 mils.

Taking these steps will prevent unsightly chemical staining/etching and keep your paint finish looking attractive.