Resin for Marine Plywood?

[JRShamblin]

I needed to redo the floors in my Bass Boat project.

I just broke down and purchased marine plywood from 84 Lumber, cost me 145 dollars for two 4X8 pieces. I figured it was better to go ahead and pay a little more to do it right the first time. At least thats what most have recommended.

My question is what do i need to do with it now?

Do i put primer on it? Resin? Epoxy primer? Or do i just cut the wood and lay it in the boat. Im just not sure on what to do. If i resin it could someone give me a link or information on the product they used? and also how much did you need of it. My boat is a 16ft boat with the floor (marine plywood) measuring 3'X13'.

I appreciate any help, as i am a newbie rookie restorer! Thanks!

 

[tinkeringwackyone]

Re: Resin for Marine Plywood?

a good exterior grade plywood would have been fine as you need to coat it either polyester or epoxy resin, your choice, and fiberglass it in place.

 

[Sean-Nos]

Re: Resin for Marine Plywood?

Hi I used west system to coat my boat If your not too sure of epoxy get the cans with the pumps, very handy,How much you use will depend on how many coats you want to give it. If it is out in sunlight you will need to paint or varnish it as it has very little uv protection.These have a lot of info and videos on how to use their epoxy.Good luck.
http://www.westsystem.com/ss/

 

[drewpster]

Re: Resin for Marine Plywood?

The ultimate in watertite coating for the underside is a coat of epoxy and fiberglass cloth. The next level is a couple of coats of epoxy alone. Sand between coats.

The next level is a coat of polyester resin and cloth. The factories usually go with a single coat of polyester resin alone.

The next level is a coat of premium outdoor varnish or polyurethane. I do not recommend cloth with it.

If you want to go even cheaper, you can used a good outdoor urethane primer and paint. But it will not yield near the protection of any of the above.

 

[ezmobee]

Re: Resin for Marine Plywood?

drewpster nailed it above^^^^

For my deck, I put 2 coats of epoxy resin on the bottoms and 1 coat on the tops. Then I installed them in the boat and added another coat of epoxy which helps to seal all the screw holes. I also added some fiberglass cloth to the seams where the boards meet.

 

[JRShamblin]

Re: Resin for Marine Plywood?

Thanks for you replys and help:

Well I already bought the marine plywood, so unfortunatley the exterior suggestion is not an option now.

As far as the wet seal reply that seems to be very nice stuff but it is so expensive and the plywood i have is going to be for my floor with carpet overtop it. so it would never be seen.

in regards to the epoxy resin, do you have a particular brand that i should use. Im trying to do this as cheap as possible since i just spent 145 for the actual floor. (i just dont want my 145 to be worth nothing if it rots in a year)

Any more help is always welcome i appreciate you guys on this board, your very knowledgable and helpful.

 

[ezmobee]

Re: Resin for Marine Plywood?

I bought my resin from here: http://www.clarkcraft.com/cgi-suppl...esin&*******=9dc4fdd1e5a2e3ba99a65448a569d333 it's a 1:1 mixing ratio which is nice and fool proof. Price is about average. Forum member Tim Fives just scored an incredible deal on epoxy from ebay so you may want to check there.

 

[osborn159]

Re: Resin for Marine Plywood?

if you want it to last even longer dont put the carpet over your deck, it holds water, poly resin is not a sure seal, another option is after resin and mat/cloth to use paint w/ a nonskid additive or buy the nonskid paint, i think adding the grit to a color of your choice is cheaper. just a thought for you, after $150 in ply, it will last longer w/out carpet.
D

 

[robert graham]

Re: Resin for Marine Plywood?

I used marine plywood for my transom and just put several coats of polyurethane on it, seems to work fine, and you can inspect/sand/recoat every year or so, just to keep it looking good. Polyurethane comes in a gallon can at Home Depot or Lowe's...I'm pretty sure mine is specifically for exterior/flooring applications. My transom is 25 years old and still looks fine!

 

[ondarvr]

Re: Resin for Marine Plywood?

Another suggestion is to read the old threads on this subject, should keep you reading for weeks.

Lots of debate on resin type, but what you need to remember is how long it lasts depends more on how good of a job you do, than the exact products used.

On a floor neither resin should be used without glass, while epoxy is tougher, both will crack over time from the stress in this type of application. The glass also increases the thickness of the coating which helps to protect the wood from moisture (neither product is waterproof). All wood should be pre-coated with resin and allowed to harden before applying glass.

Did you also check the transom? Most of the time if one's bad so is the other.

 

[JRShamblin]

Re: Resin for Marine Plywood?

Thanks Ezmobee! that what I should probably go with, how much of that Resin did you use? or better yet how much do you think i would need? again its going to be 3' X 13' marine plywood.

As far as expense wise the polyurethane seems to be a cheap route is there any drawbacks to using polyurethane as oppose to the Resin?

 

[ezmobee]

Re: Resin for Marine Plywood?

Thanks Ezmobee! that what I should probably go with, how much of that Resin did you use? or better yet how much do you think i would need? again its going to be 3' X 13' marine plywood.

As far as expense wise the polyurethane seems to be a cheap route is there any drawbacks to using polyurethane as oppose to the Resin?

Poly CANNOT be used by itself. It has no strength without glass. Epoxy does. It would still be better with glass as was indicated above but it can be used by itself and that's what I went with. I can't give you a good estimate on what you'll need because my exterior grade plywood sucked up like 3 gallons whereas North Beach did his with marine ply and only used like 1 gallon. So somewhere between 1 and 3

 

[JRShamblin]

Re: Resin for Marine Plywood?

alot of you are saying make sure you use glass. are you talking about Fiberglass Resin? if that is the case could i just buy a gallon of Fiberglass resin and be done with it. or do you need the epoxy resin THEN the fiberglass resin?

Please excuse my ignorance this is my first boat, first project, and i am a paper pusher so i dont know much about tools & restoring things.

I found this fiberglass resin.

It is a little cheaper for a gallon of it than the epoxy primer i was looking at. any thought?

 

[ajgraz]

Re: Resin for Marine Plywood?

"Fiberglass resin" could mean either polyester or epoxy resin. Either would be used with a fiberglass cloth or mat ("glass") for repair or fabrication work.

That Bondo resin is polyester resin. My Dad taught me, "polyester resin sticks to polyester resin, but epoxy resin sticks to anything." Consequently, I always use epoxy resin (and fiberglass cloth) for any repair work. That way it doesn't matter what resin the boat was made from, or what others before you may have used.

That link to clarkcraft.com that ezmobee linked a few replies back has what look to be darned good prices on epoxy resin, about 15% better in fact than what I've been buying off EBAY.

What I would do for your 3' by 13' floor is buy 2 gallons of epoxy resin, use about 1/4 to 1/3 of that total to put (at least) two coats of 33% solvent-thinned (acetone, xylene, even carb cleaner) epoxy on each side of the plywood, then use the rest un-thinned to wet in (at least) two layers of 7 oz glass cloth over top the whole installation.

(Solvent-thinned epoxy takes longer to cure, but it makes wetting out the wood with epoxy MUCH easier, and stretches your "epoxy dollar" a bit)

 

[ondarvr]

Re: Resin for Marine Plywood?

Don't thin either resin with anything, it can degrade the product significantly.

It seems like a good idea, but the chemistry of it just doesn't work.

 

[Meadfisher]

Re: Resin for Marine Plywood?

The ultimate in watertite coating for the underside is a coat of epoxy and fiberglass cloth. The next level is a couple of coats of epoxy alone. Sand between coats.

The next level is a coat of polyester resin and cloth. The factories usually go with a single coat of polyester resin alone.

The next level is a coat of premium outdoor varnish or polyurethane. I do not recommend cloth with it.

If you want to go even cheaper, you can used a good outdoor urethane primer and paint. But it will not yield near the protection of any of the above.

Hey Drew, can you recommend brands? for the first option?

 

[Meadfisher]

Re: Resin for Marine Plywood?

"Fiberglass resin" could mean either polyester or epoxy resin. Either would be used with a fiberglass cloth or mat ("glass") for repair or fabrication work.

That Bondo resin is polyester resin. My Dad taught me, "polyester resin sticks to polyester resin, but epoxy resin sticks to anything." Consequently, I always use epoxy resin (and fiberglass cloth) for any repair work. That way it doesn't matter what resin the boat was made from, or what others before you may have used.

That link to clarkcraft.com that ezmobee linked a few replies back has what look to be darned good prices on epoxy resin, about 15% better in fact than what I've been buying off EBAY.

What I would do for your 3' by 13' floor is buy 2 gallons of epoxy resin, use about 1/4 to 1/3 of that total to put (at least) two coats of 33% solvent-thinned (acetone, xylene, even carb cleaner) epoxy on each side of the plywood, then use the rest un-thinned to wet in (at least) two layers of 7 oz glass cloth over top the whole installation.

(Solvent-thinned epoxy takes longer to cure, but it makes wetting out the wood with epoxy MUCH easier, and stretches your "epoxy dollar" a bit)

Awesome advice. Im ready to see this challenge through. Man Ive missed being on here. Thanks much!

 

[jbcurt00]

Hey Drew, can you recommend brands? for the first option?

@Meadfisher avoid posting in inactive topics

Drew hasnt been back to this topic in 12+yrs

Closed