I gave up on that "gloss" stuff I found, it was ancient and pretty much flaked off. So, I used some spar urethane on the back and ends. I brushed some paint on the ends too. After one night in the shed, the ends had aleady started a little crack on both sides. Nothing big, but I was amazed on how quickly that happened even with the paint and urethane on it.
I decided to take some material off the belly, and work it down a little, and after this I sprayed another couple coats of the urethane on the back, repainted and sprayed the urethane on the ends and about 4" up each side on the belly. After all that dries, I'll clamp it to a board to help keep it from warping.
Do you think I should leave it in the shed or bring it inside? Out there the temperature is consistantly around 80-90 degrees, with moderate to heavy humidity.