Sealing Masonite

[kookenotes]

I am thinking of using 1/4" tempered Masonite for the roof of the Benroy woody I am building. It will be covered with with .040 aluminum with a one piece roof and a one piece hatch. Should I seal the edges of the Masonite, prior to installing the skin, with Epoxy, CPES, or are there any other alternatives? I understand that Masonite is tempered with a linseed oil bath so I assume I only need to worry about the edges. Also, is there a good thread out there on the use of epoxy exterior finishes under marine spar varnish? Thanks for any assistance. Bill