Spar over Masonite in California

[L8startsk8r]

Hey guys. I'm building a 3'6" mini with a 6'10" transition. I am surfacing with Masonite and plan to seal it with spar urethane. My question is, can I seal the Masonite prior to it being installed? Will it cause cracking when bending it to form? Should I just seal it once it is installed? The reason I ask is we are having an unusually wet winter/ spring and sealing it prior to installing it will give me more time to work on it while the weather is bad.

[inframan]

I'd just spar the plywood, I havent heard of masonite, even with spar, ever working out, example: http://rampplans.org/forums/?board=log; ... ;start=135

Or you could go sheet metal.