How to waterproof plywood with epoxy?

Question

im trying to built a 14 ft long boat

Answer 1

if you use marine ply, like you should for water use, give your ply a light sand before you start, just to make sure it is clean, put a layer of 4oz chopped strand glass over it, make sure you paint the ply with resin before you put the soaked glass on, dont be shy on how much resin you use either,  get it smooth and bubble free, then put a coat of gel coat over the top, it's best to use un-waxed resin for the glass and ply, then waxed gel coat, un-waxed will allways feel tacky even when set, it will make the gel coat or any other layers of glass stick to it better without having to rough the surface up, just make sure you do it in a dry clean area, preferably with no wind blowing on the surfaces, thats how osmosis gets started, it takes a few years though, you can get the gel coat tinted to what ever colour you want as well, so no need to paint, and it is a lot harder than paint it's basically resin anyway, if you do want to paint, get some polyurethane or polyester 2 pack paint, there are a few good brands out there, it's not cheap, but compared to normal paint, it is cheaper over the long term and can take more abuse, it is also easier to re-paint, you dont have to sand it back, only get the daggy bits off, clean it with a rag soaked in acetone, then paint

Answer 2

first of all you do need to epoxy to waterproof..just lightly sand the plywood, mix the epoxy and apply it, do nto be shy, put alot on.

the last comment is good, but you just want to epoxy not build a fiberglass boat.

Answer 3

Use marine ply! no need for epoxy!