Q: I have wood paneling in my shower stalls that need re-doing. I have already sanded and wiped the walls. What would be the best sealer to use?
A: Best? The best would be a moisture cured urethane, but it is not easy to come by. Offhand, I know of only one company in Brooklyn, NY currently selling it, and they sell primarily to the industry, not to homeowners. The product is extremely durable in that sort of setting, but because of the chemical involved, must be handled both with great care and proper safety equipment. By the way, I will assume you are back down to bare wood, since this finish is not appropriate over an existing finish. On the other hand, if you prefer something less than the best, but still quite adequate and more accessible, you can go with oil based polyurethane or spar varnish. As Hallack Brendan once said, “sometimes the best becomes the enemy of the good.”