I have found Citistrip the best paint remover I have ever used. However it
says it will remove polyurethane (it will not even touch it) but all other
things it works great on. Also I have some truck aluminum running boards
that the anti slip strips needed replacement. they were a pressure type
adhesive. I tried , 1 mineral sprits, 2 lacquer thinner, 3 acetone, 4
MEK. None of these would soften it. Then tried Citistrip and in about 10
minutes it was wiped off. I had a sample of it to try, now going to buy a
1/2 gallon. Found best price at Home Depot. Just thought I would let you
know about the polyurethane. WW