why noy poly resin alone for sealing plywood?

[brunolund]

just wondering, why it can't be used as a sealer? i put a single coat of epoxy sealer on my plywood floor, but that stuff is 150 bucks a gallon here. used 1/2 gallone for first coat, top, bottom ,and sides. wanted to put a coat of fibreglass resin as a top coat, just to further seal the wood. been told not to many times, not sure why though. i'm aware of it's weakness without mat, but the coat would be very thin and not for strength. my plywood is 3/4 thick. poly resin is 30 bucks a gallon, and it seems like it would work. please tell WHY it won't, and why epoxy is better.
thanks,

 

[Woodonglass]

Re: why noy poly resin alone for sealing plywood?

Poly resin has no "Binders" in the resin. Epoxy does. This means when poly resin sets up and hardens it is very brittle and breaks easily. Epoxy, because of the binders can stand up under flex and torsion and will not do break apart. When the wood flexes, and it will , the poly resin will crack and allow water to penetrate into the wood. The mat used with poly IS the binder and the poly actually "Melts or Dissolves" the glass fibers and makes the mix one homogenous mass that is contiguous. Really not that strong. The Fiberglass Cloth is where the strength comes from.

 

[tpenfield]

Re: why noy poly resin alone for sealing plywood?

If you use straight polyester, the seal will be only temporary. . .

 

[Yacht Dr.]

Re: why noy poly resin alone for sealing plywood?

just wondering, why it can't be used as a sealer? (snip) .. please tell WHY it won't, and why epoxy is better.
thanks,

Good question brunolund .. and the final answer is Application,application and application..

Decks do not normally Flex around as such..so you can use epoxy or poly..

However.. what are you Topping your deck with. Carpet ? Flexiteak ? Paint ?

Your Wood deck is only a substrate of what your finish is going to be. You Must adhere to the standards of the TOP SURFACE application. ( You have to think Backwards when doing things on boats lol .. your last coat dictates the coat before it and the coat before that until you backward engineer to the wood )

Will Poly resin work for a 'sealer' .. Depends on the final application of your surface ( where your feet hit the deck ).

Sometimes Epoxy is not better..depending on the Final Application ..

I hope Im getting my point across here .. Application .. ..

YD.

 

[jigngrub]

Re: why noy poly resin alone for sealing plywood?

If you want a suitable top sealer and don't want to use epoxy, use an exterior grade Spar urethane.

Where are you that makes epoxy $150 a gallon??? Timbuktu?

 

[brunolund]

Re: why noy poly resin alone for sealing plywood?

Canada. seems like most stuff is twice the price here. the floor will have snap in carpet on top
any more tips?