 Put a marine urethane on it, not a polyurethane on it. Or you can paint it. And a lot of people do. They just paint it. They get tired of messing with it. You know, regular polyurethane, when I say you don't use regular polyurethane or regular varnishes, it doesn't have much UV protection, if any. Whereas a marine urethane or a spar urethane does have UV protection.