Professional Carwashing & Detailing

Acid Rain: Buffing steps

January 15, 2014

This is the fifth part in a six-part series covering the repair process involved with acid rain and chemical etching.

For the purposes of this article, we will consider the following project: you are repairing a 1999 model vehicle. The paint has etch marks scattered across all of its horizontal surfaces, requiring that several large areas must be replaced. Please note that the items listed above (in particular, the paint thickness gauge), should be used in the following chemical etch repair process.


Start the actual etch removal process by buffing, since this is the least abrasive approach and you want to remove as little of the clear coat as possible. Apply a strip of 800 or 1,200 grit compound to the test area. Then, using a high speed buffer and a clean wool cutting pad spread the compound on the panel.

Buff the area, moving only back and forth lengthwise (from the back to the front of the car) on the panel. Tape any feature lines and panel edges to avoid burning through the paint in these areas. If necessary, you can buff these spots later by hand. After several passes, wipe the area and check your progress. If etch marks are still visible, apply another strip of compound. Check to see that the pad is still clean, spread the compound and buff the area again.

Since buffing can remove a surprising amount of clear coat, you want to work for a short period of time and check the results frequently. Often, one or two buffings with the proper compound will do the job. If the etch marks are removed, all you would need to do from this point is polish and then wax the area to complete the repair. Unfortunately, sometimes the etching goes deeper than buffing alone can repair. In this case, you will have to sand.

Here are the other articles in this series:

4. Acid Rain: Preliminary repair steps

3. Acid rain and rotary buffers

2. What is a paint thickness gauge?

1. A car that's been hit by acid rain comes into your shop. Now what?