Wet sanding after touch up paint?

[FX4619]

I have a chip on my bumper that I filled in with touch up paint. What is the correct process for wet sanding and polishing out the correction? I have never wet sanded on a vehicle before and quite frankly it makes me nervous. Does Meguiars have any training videos for this? Thanks!

[Michael Stoops]

Re: Wet sanding after touch up paint?

We don't have any videos for sanding just on a small chip, and any spot repair videos we do have involve the mini air powered DA and rotary tools, so those won't help you much either.

This should help you, though: Tape off the surrounding are, leaving no more than 2" clear all around the chip. Get some 2000 grit wet/dry sandpaper, soak as directed, and then lightly sand the paint blob, going slowly, until it's level with the surrounding area. But never do this with just your fingertip as a backer to the sandpaper - that will cause the sandpaper to ride up and over the paint blob, sanding it lightly on the top but also sanding the surrounding material as your fingertip (or thumbtip) conforms to the paint blob. You want to level this paint blob, so find a small block of plastic, wood, etc and use that as a backer to the sandpaper. Sand in straight lines, but you can go in multiple directions if you like - just don't sand in a circular pattern. The goal here is to level that blob down to the level of the surrounding paint, and (not much) more. Keep the area wet, and take your time.

If you have a DA buffer you can use that to buff out the 2000 grit marks. It helps if you have 4" pads to do this, and maybe some M105. You can certainly try Ultimate Compound by hand with a foam wax applicator pad. Since you're working such a small area you can put a lot of energy into even by hand. In fact, you can put so much energy into a tiny area by hand that it's possible to rub right through the clear coat. Yes, by hand. We've seen it plenty of times. So go easy here, too, at least at first, and monitor your progress. Again, take your time.

[FX4619]

What are the signs of going through clear coat? How do you know that you have buffed through the clear coat? Thanks for explaining those steps. I don't have any M105 but I'll give it a shot with UC and a 4" polishing pad.

[FX4619]

Anybody?

[Jeff120]

Re: Wet sanding after touch up paint?

When the sanding dust goes from clear to the color of paint, and when the finish is dull and doesnt absorb water anymore, you have dont through, it really doesnt take much.

You may want to look into the Lanka blob eliminator. It works pretty well for getting the extra paint off and its much safer then wet sanding for sure.

[Michael Stoops]

Re: Wet sanding after touch up paint?

It can be tough for a novice to judge when they've gone to the limit when sanding clear coat. If you're sanding a full panel you're going to be using a paint thickness gauge, or watching for the low spots in the orange peel to show signs that the sand paper is finally reaching it, etc. If you wait until you start to pull color it's too late.

But for paint chip repair with a blob of paint built up over the top of the surrounding paint, and using the technique outlined above, and taking your time, you shouldn't run the risk of sanding through the clear. If you skip the block behind the sandpaper and just use your thumb to hold the paper, you'll actually start cutting the surrounding clear long before you level that paint blob. So, under no circumstances should you forgo the use of a backer to the sandpaper.

[FX4619]

Sounds good, thank you!