[firecat1981]

I am wondering how water proof fiberglass is? I have some parts that will below a deck and will have water run along it. I know alot of things get sealed with epoxy.
So basically I'm asking if it can't be seen and will have water running along it does it need to be painted or is the fiberglass ok as is?

 

[Brett]

Re: Waterproof epoxy

Epoxy impregnated fiberglass is waterproof. Polyester resin and fiberglass is not.
You can epoxy coat plywood with a prime coat (it soaks in) and a gloss coat to make the plywood waterproof.
If the boat is to be left outdoors, the epoxy exposed to sunlight will need to be painted or spar varnished.

 

[firecat1981]

thanks Brett, basically I was wondering if I need to paint under the false floor I'm planning on or if the water would eat away at it. it won't be exposed to the sun so I think I'll be ok.

 

[kuzus]

If you are using polyester resin, I would coat in with interior gelcoat. It's ok if plain fiberglass and resin gets wet, but it is not suitable to be underwater or wet for extended periods of time. If the area you are talking about drains well and won't hold condensation, it should be ok.

 

[firecat1981]

it's epoxy, and it's a part that will drain to the back bilge area, so it will be wet often.

 

[kuzus]

as long as you seal the fiberglass completely, water won't get to it