TIL a trick for getting rid of those tiny air bubbles in polyurethane

I was finishing a maple tabletop and the bubbles just wouldn't settle. I read online to thin the final coat with about 10% mineral spirits and apply it with a foam brush instead of a regular one. The finish leveled out perfectly with zero bubbles. Has anyone else tried this method on a tricky wood grain?

3 comments

3 Comments

the_matthew1mo ago

How well does that work on something really porous like oak? I had the same bubble issue on a red oak floor and thinning it was the only thing that saved the job... the foam brush made it go on like glass.

lilykelly1mo ago

Ever try a conditioner first? I had a pine table that drank finish like water until I sealed the grain with a thin wash coat (it was a real game changer). That prep step basically solved all my bubble problems before they started.

samjohnson1mo ago

Thinning it down just hides the problem. You get bubbles because you're working it too much with the brush. A badger hair brush lays it down smooth without all the fuss. Tried foam brushes once, left bits in the finish. Real bristles are the way to go.