Thinking about sanding between coats of paint on a touch-up paint project? Think again.
We usually recommend not sanding between coats of touch-up base color paint, clear coat, or primer. However, if a little dirt lands in the paint, you may let the touch-up paint dry and sand out the speck. If you're having an issue with too much texture or getting runs in the paint, you may want to sand as well.
The reason we usually recommend that you not sand between coats of paint is that the paint could still be too soft to sand, despite it feeling dry to the touch. Fresh paint is often softer than it looks: It was developed to be flexible enough to paint on plastic, and it has a bit of retarder in it that helps it remain glossy in less ideal application climates. Even though it may feel dry to the touch, it may be a little gummy, and sanding in between coats of paint can ruin the paint job. Then, you'll have to sand the finish down and start over. No one wants that.
Sanding between coats of the base coat color should only be done if there is something wrong with the application. This is especially true if you're tempted to use sandpaper between coats of paint with a metallic or pearlized look. Sanding metallic or pearl colors can destroy the effects, and that will shift the color or the pattern of pearl or flake. If you have to sand between coats of paint at any point, it must be re-coated with another layer of color before moving on to the clear coat.
What About Sanding Between Coats of Primer?
Sanding between coats of primer is pointless. Once all of the primer is dry, you should sand the primer before moving on to the base coat, but sanding between coats of primer will just extend how long it takes to complete this phase of your paint job. Sanding at the end of the primer step yields the same results in less time.
Should You Sand Between Layers of Clear Coat?
Sanding between layers of clear coat is also not recommended. Wet sanding and polishing the final layer will yield a better result than doing it between each coat. Clear coat layers are also thinner than they look. If you sand through the clear coat into the base coat layer, then you have to respray the base coat to cover the damage and then blend it back into the existing panel. If you have some dust or dirt on the surface, you can still sand it out and respray more clear coat, but expect the job to take longer.
Keep in mind that a modern body shop would only sand between coats of paint if they absolutely have to because of an application error. With clear coat, they would sand it before polishing only if it was necessary: The goal would be to avoid it.
We hope this article helps you understand why sanding between coats on your touch-up paint project is probably a bad idea. If you need further help, give us a call!