epoxy resin coat over cpes coat ?

[phishown]

Hello I'm in the process of restoring a Chesapeake Deadrise Charter Boat. I have a question regarding the underwater application of cpes. I am currently sanding the bottom of my boat and it was originaly coated with epoxy under all the coats of antifoulant. There are a few areas where the epoxy is rubbed off and delaminated. I decided not to take the entire bottom to wood because for the most part the epoxy coat is doing it's job. My question is, after I sand the bare areas and the delaminated areas to clean the wood and apply CPES should I put a coat of epoxy resin afterwards? Thank You for all your answers! I have many great ideas thanks to wooden boat forum.
38ft deadrise 14.3 beam
Mark

[R.Floyd]

Hey, you gotta dead-rise in Alabama?

Are you saying that the bottom planking was sealed with epoxy prior to bottom painting? Ain't no Deal Island boat! Sure, CPES it first...but why? If the wood is dry enough for CPES to soak in, shouldn't it be dry enough for an epoxy Like West? You can coat over CPES but you should sand the surface to give it "mechanical tooth" also.

Prefferably, skip the CPES. It is a sealer. The epoxy gives it more strength. Especially in any reglueing of delaminations.

[ 03-06-2005, 07:04 PM: Message edited by: R.Floyd ]

[phishown]

Had her shipped last week from Deltaville, Va to Mobile, AL. Kinda pricey for shipment.

[Bruce Hooke]

I'm a bit suspicious on one point, which is your reports of the epoxy "delaminating." Epoxy is awfully tenacious stuff and I it seems like its mighty rare that it delamintes (unless, of course, it was applied to a surface that was not clean, bare wood). There are two things I would consider:

1. Are you sure it's epoxy and not polyester resin? Polyester resin ("fiberglass") is much more prone to delaminating. It is not uncommon to find cases where you can literally peal whole sections of it off, which leads to my second point:

2. Whatever it is, if some areas are delaminating I would be checking VERY carefully to make sure that other areas are not on the verge of delaminating. It is very tempting to not pry to hard on sections that look like they are sticking because you don't want to know that awful truth that they are not really sticking very well, but it's better to find out now rather than later...

[phishown]

The only delamination is on a couple of plank seems where I assuming the flexing of the plank cracked the coating. It's only where water has penetrated the cracked coating...... about a half inch on each side of the crack has delaminated.

Would applying the epoxy over the entire bottom after removing all old antifoulant be a good idea?
I would definately put a tooth on the old epoxy coating before recoating with new?

[paul oman]

Some good comments here. Polyester resin does tend to 'delaminate' after a few years. Also it could have been coated with a regular (brittle) maire epoxy which will expand and contract with heat, while your wooden hull expands and contracts with mositure content. Instead of a marine epoxy use a more flexible epoxy paint which will move with the wood.

Adding solvents to epoxy (such as CPES etc) does add in penetration and thus provides a stronger bonding surface (a primer). This subject tends to be a can of worms on this forum so lets just say it is the same as the folks that solvent thin their first few coats of varnish...

paul oman
progressive epoxy polymers
(company info given in the name of FULL DISCLOSURE)

[Ian McColgin]

Are the seams tight seam (wood to wood), caulked or splined?

[phishown]

the seems appear to be wood to wood that have been glued with epoxy and fastened with stainless

[R.Floyd]

Paul, are you suggesting adding CPES to an epoxy such as West System? I've never heard of that.