Why You Shouldn't Sand Between Coats on Touch Up Paint Projects

touch up paint sandpaperThinking about sanding between coats on a touch up paint project? Think again.

We usually recommend not sanding between touch up base color paint, clearcoat, and primer coats. However, if a little dirt lands in the paint you may let the 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.

The reason we usually recommend not sanding is that the paint could still be too soft to sand despite it feeling dry to the touch. This means you may have to sand the finish down and start over. No one wants that.

Actually, sanding between coats of primer is pointless. Once primer is dry, you should sand the primer before moving on to the basecoat color. Sanding between coats of primer will just extend how long it takes to complete the phase, while sanding at the end of the primer step yields the same results.

Sanding between coats of basecoat should only be done if there is something wrong with the application. 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 the basecoat at any step it must be re-coated with another layer of color before moving on to the clearcoat step.

Sanding between layers of clearcoat is also not recommended. Wet sanding and polishing the final layer will yield a better result than doing it between each coat. Clearcoat layers are also thinner than they look. If you sand through the clearcoat into the basecoat layer, then you have to respray the basecoat 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 clearcoat - but expect the job to take longer.

The paint is softer than it looks too. It was developed to be flexible enough to paint on plastic, and it has a bit of retarder in it which helps it remain glossy under less ideal application climates. Even though it may feel dry to the touch it may be a little gummy and sanding it can ruin the job.

Lastly, a modern body shop would only sand between layers of basecoat if they absolutely have to because of application error. With clearcoat 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!