CPES Question

[REBrueckner]

Believe it or not, Home Depot has 2ft x 3ft pieces of 3/4 inch plywood, and other thicknesses, in birch, oak, pine....etc. It's an easy source if you have HD nearby. The hardwood plywoods I believe have no voids and a large number of layers....

I assume CPES is a thin epoxy fiberglass?? If so you can use git rot or just some epoxy fiberglass... Plain old paint on wood alone, no fiberglass resin, will outlast all of us as long as it's not sitting in bilge water. Our interior floors are softwood beams and plywood and just fine after 30 years...

[Jackman]

These pieces will be in the bilge...holding up the mufflers and I will also be making a new battery box. So water contact will happen. Encapsulating the plywood in CPES is the best way to approach it as far as I can see.

[34Hatt]

I use MDO also know as Dura ply it is used for signs out side Strong, flat seal the edge with epoxy and it last for ever! I have seen it used at work here outside in the weather and some of it is 20 years and counting. I pay about $55 for a 4x8 sheet of 1/2".

[Jackman]

Well,

I got the birch plywood, believe it or not at Homedepot. (About $45 per sheet). Cut everything up to about the correct size and put the first coat of CPES on the first set of sides. Do you think I need a second coat...especially on the battery box sides because they often get exposed to direct bilge water?

I'm doing all this at my girlfriends apartment in Philly on the second story roof. Hopefully I don't kill any city sewer rats with this stuff. I don't smell it while doing it outside but while in the boat it was strong enough to kill roadkill all over again!

[Bob Bradley]

Whatever you decide on, don't use red oak. It soaks up water like a sponge and will rot very quickly. If you rip a small piece of red oak, say 3/8" x 3/8" x 4", you can actually suck water thru it like a straw. White oak is the only oak you should use in a boat. It has chemicals - acids, I believe - in it that actually kill rot spores. I rebuilt most of my old wooden Chris, and every replacement piece received at least 2 coats of cpes.

[Passages]

Was wondering of I could get the same result as CPES using West System Epoxy thinned with acetone?

Or similar products such as Git Rot, Gluvit or West Marine Penetrating Epoxy

[Banshee36]

I was looking at the price differences between marine grade plywood and red oak. Of the two which would you use with CPES? I didn't see much price difference between the two woods (for the amount I'd need).

Never ever put red oak in a boat, only Whiteoak, the red rots out must faster.
JW

[Banshee36]

Was wondering of I could get the same result as CPES using West System Epoxy thinned with acetone?

Or similar products such as Git Rot, Gluvit or West Marine Penetrating Epoxy

You could use MAS Epoxy, it is a much thinner viscoaity and stronger than West system.
JW

[mike]

At the risk of sounding like a commercial for Smith & CO, I can't recommend it enough that you talk with Steve Smith. He has a Hard Wood Epoxy system that is flexible and when used in conjunction with his CPES will be far stronger that your base material. I have done peel tests and found that glue joints when done right do not fail, the failure is in the adjecent wood structure. Using the CPES helps to strengthen that interface, hence a stronger more flexible joint. His products have stood the test of time in many off-shore power and sail boat applications. Talk with him directly, he is a no-BS guy, you won't be sorry. Mike

[Genesis]

The Smith epoxy system is awesome.

Thick stuff when mixed and doesn't flow for shit. But it does set up with some pliability to it and makes for an ungodly-strong joint with some flexure capability.