I bought a table someone had painted over the original finish. I used a gel stripper to remove the paint, but it went through the finish under the paint, as well. But only in spots. Paint is gone, and most of the original finish. Since the stripper ate into the finish, I did two more applications to try to remove the rest of the finish. Some spots just will not come off! I believe it is polyurethane since lacquer thinner will not dissolve it. Also, the instructions say to remove any residue with mineral spirits, so I tried that first with no luck. The wood is in very good condition - I just want to return it to the natural wood finish - with polyurethane, of course. What do I need to do? I was afraid to recoat it since I'm afraid the spots will show.