Refinishing an old desk, the top of it has a finish I can't figure out.

I tried using an orbital sander on it and it was nearly impossible to even scratch it. Then I tried an acetone sample on on the finish, and it beaded and then evaporated. So I'm assuming it's polyurethane, but is there anything else it could be before I go buy a polyurethane stripper?

The rest of the desk is almost completely sanded down so I'm ready to get to the next step.

Submitted January 23, 2015 at 11:37PM by j2k3k http://ift.tt/1CuEyHe