Q & A: Sanding Scratches Revealed

Sanding

Unwanted scratches pop out under a low-angle light.

Q:

What can I do to see sanding scratches before I apply stain? I always miss some of them until it’s too late.

A:

Doesn’t that drive you crazy? Just when you should be home free, wham! Now you’re stuck with a lousy finish and there’s no way out.One simple measure can prevent this from happening again. Use a bright light to make the scratches visible before you stain.

A portable trouble light held at a very low angle to the wood makes sanding scratches stand out like long shadows at sunset. This raking light is the ultimate test for a well sanded surface.You may see random-orbit sander swirls that you never knew existed.

Check your progress with the light between each grit of sandpaper. As you move from coarse to fine paper, the trick is to remove all the scratches made by the previous grit. The only way to ensure that you’ve succeeded is to actually see the scratches, and that’s where the light comes in.