So here is my plan.
1) gonna sand the entire trailer with 80 or 100 grit paper, I need to smooth out some checks and cracks etc, in the ply.
2) wood flour/epoxy any gaps screw holes etc that i may have. I need/want to fiberglass some of the seems on the roof, I will do these just after any gaps are filled with the epoxy mix, and I will use a bondo squegee to wet out the glass.
3) Hopefully on the same day apply one coat of epoxy.
4) next day, give the epoxy a quick sanding with 100 grit to give it some tooth and lay another coat of epoxy possibly 2.
Again thanks everyone.