Cpes and rot

[JohnPlatou]

Just put a coat of cpes on the sripped ribs of my Cruisers 202. Some spots turn back others look like they are varnished. Does the black color indicate that the rot has progress to the point cpes will not work and the rib needs to be replaced. Bottom plywood is off, so splicing a rib would not be that difficult.

[ 02-01-2004, 10:37 PM: Message edited by: JohnPlatou ]

[Ian McColgin]

All the black from rot that I've ever seen is apparant before cpes-ing but perhaps with oak the cpes could enhance it. Even after the cpes has cured, you should be able to tell if it's rot by gougin out a little and inspecting. Maybe gouge out a bit of cpes-ed good stuff for comparision. On the side of the grain (not end grain) the cpes will penetrate into rotted wood far more deeply than into sound wood. Also, the rotted wood will not have an intact structure - no splinters.

G'luck

[Wild Wassa]

CPES will turn sound Coachwood black and Coachwood is the colour of a Caucasian's skin. It turned my boat black.

The rot on my boat was different, it was turned to 'jet black'.

Warren.

[Wild Wassa]

This is how black, rot on a basic marine ply can go after a good wet out with CPES. With the silver bits back on, ... it will look like sap vains, ;) .

http://www.imagestation.com/picture/sraid102/p4cf8df7e83e049937ec7f25481f7fa85/f9b3b76e.jpg

http://www.imagestation.com/picture/sraid102/p89c07e42beb3a655f18c506f08442227/f9b3b724.jpg

Warren.

[ 02-06-2004, 05:35 AM: Message edited by: Wild Wassa ]

[JohnPlatou]

Is the black rot stopped or is it still alive and still able to spread?

[Wild Wassa]

JP, CPES forms an epoxy matrix that encases the rot depriving the rot of nutrients. Starving the rot. Hence timber needs a real wet out. The rate at which CPES disappears into the timber is awesome? The matrix appears to remain slightly porus (I think) until the next few coats of CPES or normal epoxy fill the very fine voids. After a few months Cpes draws the above coats further in to the wood/voids, a bit like a tight shrink wrap (I find). Something has worked.

Smith and Co say in their data sheets, pick off loose timber/rot with fingers, which furthers to a wire brush or a circular wire brush in a drill. Timber that has seen moisture describes itself quite well under CPES, and appears to look worse than it is I find.

Sea Scout Heron box (Douglas Fir), had hardly any visible rot, yet it went very black in places, CPES seems to penetrate the areas very well. Unless the timber still seems overly porus/spongy after a good wet out with CPES, it is probably sound. Check well though.

Warren.

[ 05-11-2004, 02:15 AM: Message edited by: Wild Wassa ]

[Bob Perkins]

You are probably having the same issue I have had.

The CPES is penetrating the wood differently depending on the grain. I've done some spot work on teak toerails and some areas are fine, others darken. There is no rot in my case - the varnish just needed to be redone in these areas.

This is just like using stain on pine that has not had a seal coat put on. Pine gets blotchy because of how it absorbs the stain.

I think the CPES is doing the same..If I'm interpreting the question correctly.

-------------
Regards,
Bob Perkins

My out of date site is at:
http://robert.perkins.home.comcast.net/

My Current project is at:
http://www.imagestation.com/album/?id=4291051329
-------------

[paul oman]

Both the 70% solvents and the 15% curing agent in the product will kill the fungus and perhaps 'bleach' it out a bit. Interesting observatiions! Could be the remaining black did not get 'reached' by the solvent thinned epoxy.

alternative method would be bleach then solvent thinned epoxy.

paul
progressive epoxy polymers
www.epoxyproducts.com/marine.html (http://www.epoxyproducts.com/marine.html)

[Wild Wassa]

Originally posted by paul oman:
"Both the 70% solvents and the 15% curing agent in the product ..."

I wonder how much of the stuff just evaporates, it sure smells like it evaporates.

It is a good point about how deeply CPES penetrates the rot, the Douglas seems as though it is designed for CPES, ... just a fluke of nature?

The Heron box, I wire brushed the rot that was under the gudgeons, to the point where I'd ground tramlines. It was that, the timber still showed rot after CPES'ing that prompted the photo.

I don't really restore boats, I conserve them by taking off minimum amounts of timber. CPES really suits this process.

Warren.

[ 05-12-2004, 06:44 AM: Message edited by: Wild Wassa ]

[formerlyknownasprince]

Warren

I know it's off topic a bit - but how does CPES compare with Everdure?

Ian

[Wild Wassa]

IG, I haven't tried Everdure. TPRDA (a timber preservative and reactive diluting agent) mixed with epoxy was my wet out prior to using CPES and still is on new timber. It is a fraction of the cost of CPES, about a quarter the cost when used as a working strength dilution in epoxy (the cost includes the epoxy).

The reason for using TPRDA over a denatured alcohol as a thinner, is that a denatured alcohol (like denatured ethanol) is not a reactive agent with BoatCraft Pacific's epoxy (how posh is that for a banana bender's product?). The epoxy's structure will be weakened, BCP says.

Warren.

[ 05-12-2004, 07:36 AM: Message edited by: Wild Wassa ]