I polyurethaned my table and when it dried, it had spots. That is the best way to explain it. It looks like the eraser-sized spots are bare wood, almost like something made the polyurethane push away from the wood as it dried, leaving 100 spots on the table. I lightly sanded it and it just looks like the spots are lower than the smooth polyurethane. Almost like the wood just repelled the polyurethane. So I lightly sanded and then re-applied another coat and as it dried, what do you know… the spots came right back like the polyurethane did not want to stick to the wood in those eraser-sized spots.
So for those experienced wood workers out there, please help me with this baffling issue to try to get a smooth application.
Best Answer
Most likely you have spots of contamination such as oil or wax impregnated into the wood. As much as you may not want to hear this, I fear you may need to strip the table top again and sand the surface more completely. When the surface is clean and sanded, you can mist the surface with a little water to see if any areas repel the water. Don't let the water stand on the wood, dry it quickly after your test. This may help you determine if more sanding or degreasing is necessary to remove the contaminated areas.