1. Autos
You can opt-out at any time. Please refer to our privacy policy for contact information.

How to Wet Sand Your Car's Primer or Paint


1 of 2

How It's Done
Sanding Supplies

Wet sanding spray bottle and sand paper.

photo by Matt Wright, 2013
Wet sanding is an amazing process that, when done properly, can result in a surface that's as smooth as glass. Whether you're talking about paint, primer, bare metal or anything in between, your car's body can be smoothed by wet sanding. Let's get down to the process of wet sanding, also known as color sanding when using this method to add shine to a finished paint job. First we'll talk about what you need to get the job done, then I'll tell you the finer points of the sanding process. Finally, we can get into the esoteric side of body finishing and sanding.

What You'll Need:

  1. A car or truck that needs some smoothin'
  2. Spray Bottle
  3. Wet Sandpaper in varying grits
Good spray bottles can be bought at just about any store you can think of. Home repair stores always have them, but other box stores and grocery stores usually have bottles in the cleaning section. Be sure to buy a bottle that has an actual spray pattern. In other words, you don't want a spray bottle that throws a thick splash of water, rather you need more of a sprayed pattern that can saturate your work surface while you use one hand for spraying and the other hand for sanding.

Choosing what grit sandpaper to use is important. If you start with a grit that is too coarse, you'll be creating more work for yourself and might be left with a thinner paint or primer coat than you wanted. Start with too fine a grit and you'll be sanding until your arm feels like it's going to fall off. A little experimentation will help. As a starting point, if you are sanding a coat of rough primer, you can start with a 400-grit sand paper to knock down all of those little bumps. After some time with the 400 grit, you can move to a 600-grit paper to give yourself a nice, smooth surface to work with when you are painting the car. If you are wet sanding a finished paint job, you definitely do not want to start with a 400 grit sand paper. Too harsh! You'll be ruining your paint finish just so you can do lots of work to restore it again. For a finished paint job that just needs a little more smoothness and shine, start with an 800, or even a 1000 grit sand paper.

Remember, when sanding anything, it's always important to take it slow. Let the sandpaper do the work, and don't apply too much hand pressure as this can cause grooves or uneven sanding. And we both know what that amounts to -- more work!

See More About
  1. About.com
  2. Autos
  3. Auto Repair
  4. Fix It Yourself!
  5. How to Wet Sand Automotive Paint Finishes

©2014 About.com. All rights reserved.