Hi 72cheyenne,
I just did mine last year. I rolled all surfaces of the plywood in poly resin. Once it was dried, I then screwed the boards down in place and rolled over the top with resin, a layer of chop strand, then resin until it was saturated.
A lot of guys will say not to use polyresin because it is a wax based cheaper product but some of us are on a budget. I found a couple of mistakes I'd do different when laying my boards in. First of all make sure any low spots will allows the water to drain to the drain plug, NOT to the back corners. I didn't pay attention to this.... hopefully it doesn't bite me.
Second issue; I have noticed a slight squeak where the two boards butted up. You might want to put cloth between them before covering over with cloth, or maybe even screw a backer board to the bottoms of both boards at the joint to reduce movement between the joints when you walk on them later.
Lastly, I bought Kiwi Grip, which I do like, but it is a pretty solid product when cured. The poly resin will absorb more water than epoxy resins, so it will expand. I ended up with water in the boat about a week after coating the deck and the water seeped into an imperfection in the Kiwi coating. Long story short, the poly resin expanded and blistered some of the Kiwi Grip up. I'd recommend something you're okay purchasing every few years to re-coat the floors with if using epoxy. My low spot was an old in-floor fuel bay which I converted to a fish box so I'll probably use Bilge Coat there and call it a day.
If you haven't bought the fiberglass you may want chop strand. It lays a little easier, uses less resin (I think) and supposedly is stronger than woven mats because chop strand is omni-directional while woven material only goes two directions.
This all comes from someone who doesn't know, but has done it. Take with a grain of salt.
Removing those floors is nasty business isn't it!
