Floor replacement paint

[SenorL]

16 foot Alumacraft floor replacement. Decided to use marine plywood, epoxy and paint. Should I epoxy and paint top, edges, and bottom of the plywood or leave the bottom bare so it can dry if it gets wet?

 

[86tuning]

I have no experience with epoxy, only with spar urethane and boiled linseed oil. It holds up really well, especially if the boat is covered when not in use. I met an older gentleman with an old sailboat swears by this stuff.

My floor is sealed on all sides with old-timer's formula and has held up well for a decade. Liberally soak the edges with it and coat both sides until the wood won't soak up any more. Apply 2-3 coats allowing drying time in between. Then paint two coats with spar urethane. The idea is that the thinned paint will soak in and protect the wood as much as possible.

Old timer's formula is a 1:1:1 or 1:1:2 mix of the following:
Spar urethane/varnish
Boiled Linseed Oil
and Mineral Spirits (thinner)

Like any paint finish, it can wear over time but it's trivial to clean and repaint it in a few years. If you're making holes in the wood to mount your floor and can pre-drill them, you can also soak the holes with the same old timers formula to protect those interior edges.

 

[pgobeille1]

Last winter I used 5/8" BCX plywood from a big box store, and on the C/up side fiber-glassed with 1 layer of 1 1/2" oz chopped strand mat. Then painted with i coat of Rustoleum Marine Primer, then 2 costs of Valspar Oil Porch and Deck with their non-skid additive in the second coat. On the B/down side only I applied 2 coats of epoxy resin, 4 on the edges, and filled voids with epoxy filler. We fish, shrimp, and crab hard under Florida sun and salt and the deck has held up extremely well so far.

 

[DaleH]

For epoxy I coat it all ... with multiple thin coats (same day) on the edge grain. For any through holes, I use the 'epoxy plug' method - see here for details: https://forum.tinboats.net/viewtopic.php?f=3&t=47405&p=474460 ... where no other finish can do that!

Boat pieces I epoxied 30-years ago are still in use and look like new, less whatever paint finish was put over it, but the coating is still integral. Done once ... done right ...