Note, this is not for exterior use.
We bought an old Buffet and converted it into a vanity for our bathroom remodel. At the time we thought it was a good idea to seal it with a waterproof sealer and selected a deck sealer at Home Depot to accomplish that task.
We have yet to get to the point where we are installing the vanity in the bathroom, but while it has been sitting in the garage, I have noted that the surface is slightly tacky.
I also observed that a separate dresser that we rehabilitated and coated with polyurethane has a smooth glossy finish that is not tacky at all and seems to be waterproof(?). So we would like that on that vanity.
So my question is, Can we put a coat of polyurethane on top of the deck-sealer-treated Vanity? I.e. Will the polyurethane adhere to the vanity? Should we lightly sand it before application? Or is there another way to get the nice smooth glossy non-tacky finish?
As an aside, why would the deck sealer treated vanity be tacky in the first place?
UPDATE: OK, here is the stain and the waterproofing sealer that was used. My wife doesn't remember how many coats she applied. She actually disagrees with me calling it "slightly tacky" and says I should describe it as "if something sets on it awhile, it can very slightly stick to the surface". She says that's not "tacky".