Preventing Bubbles In Urethane Floor Vinish

Stain that has not dried before the first coat of finish can cause bubbles.

Preventing bubbles in urethane floor vinish. There are several things that can cause bubbles in the finish. I was applying semi gloss finish polyurethane on an oil stained birch tabletop. Stir the can prior to use and take your time. Nobody wants to do all the work of refinishing and end up with bubbles in the finish.

Diluting the poly. Brush out bubbles in a fresh polyurethane finish. Finish brushes delicately lay on a thin clear coat to accentuate the surface below. Heavy coats of paint levels as it dries flattens out to hide brush marks and minor defects.

I had tried every option i could think of. However if you re not careful small air bubbles can mar the beauty of the finish permanently. Sanding between coats with very fine grit paper 220 and finer. I had similar problems with very fine bubbles in topcoat.

When the finish hardens you have to sand them out and apply a new finish. The most common causes for bubbles are shaking the can and improper brush prep you don t stick a brush into the finish without first soaking the bristles in mineral spirits for oil based polys or in water for water based polys. The only remedy is to sand out the bubbles and apply another coat of finish more. Some brands of finish are known to bubble more than other brands.

Applying polyurethane and most other finishes in heavy coats creates bubbles puddles and runs and becomes a defect in and of itself. This happens to floor finishers who drag the finish applicator aggressively and then must stay off the floor until the finish dries. To prevent air bubbles from occurring at all follow these tips. Stir the contents instead with a paint stick in a gentle swirling motion.

By the way water.