Thanks washington taco - to be honest it was my buddy Don who convinced me to go the trailer route (his build
here)
The plywood was sanded and cleaned using some prep materials (i forget exactly what, it was a remnant from a previous project) then treated with
about 5 coats of CPES. I purchased it
here. Seems to have sealed the plywood very well but be warned, this stuff STINKS. I don't catch much of an odor now that it's cured for a while, but I did note some stench in the rear compartments in the heat of the summer when they've been shut up for a while. I expect this will fade over time but I may look for a sealing type paint to coat the compartment interior for both the odor blocking feature and to clean it up a bit more from the otherwise unfinished plywood.