how well do epoxy rot replacement schemes hold up

[capatsue]

I am skeptical about Dr. Rot and the like's claims for penetrating epoxy as a cure for rotten wood at least below the waterline.
I am seeking experiences of others who tried this technique to repair a bad spot below the waterline in freshwater.How long did it last?
We have worm damage inside a rudder trunk (Maybe no actual rot is present. yet.) in a salt water boat that was just brought to freshwater. The other owner wants to stuff epoxy in the worm holes(the holes are big, probably 3-4 cubic inches anyway.) I want to soak it up with cupernol and then use a liner inside the shaft to try and seal water off from cavities. I argue the brittle epoxy will eventually crack away from wood, allow water intrusion and conceal on going rot underneath and maybe even trap water to promote rot.
If plastic fix lasts ten years maybe we don't care! So how long does Dr. Rot's cure work for? any experience out there?
ps I had several bad git rot experiences years ago hence my skepticism :any thoughts to keep old schooner rudder shaft tight appreciated.

[Kyle]

Capatsue,

There are alot of diffrent epoxies. If the wood is brittle and a flaking away no miracle goo is gonna fix it. There is a produtct that is call Clear Penetrating Epoxy Sealer. It is made by Smith and Co. This stuff is diffrent than hard epoxies. It is a flexible sealer that allows moisture,i.e. vapor to escape from the wood. It works hand in hand with the fill-it , a two part filler also made by Smith. Huge #'s of people in the A.C.B.S. swear by this stuff. Hard epoxies encapsulate the moisture from the inside and allow the allready present rot spore to start munching. I really don't have an answer as to use or not to use. The Smith product has it's merits. I am using it as a primer and sealer with all the wood that i'm replacing on my Elco. Where the topside frames are missing some of the material but are still essentially solid the C.P.E.S. and fill-it is working great. I don't feel that it is a substitutue for solid wood however.
Good Luck,
Kyle

[ironpirate]

I used a product from Abatron when I found some rot in my Log Cabin, Also used some from Dr. Rot. There both good products. The Abatron was thicker and easier to work with. But, They are amazing products. Dried harder than wood, Sanded and stained well. When finished, you couldn't tell it was there.
Seacast in Daytona also makes pourable transom repair. I've got a friend who used it on a completly rotted transom and swears by it. They all have web sites. Good luck.

[PAR]

Injecting epoxy into small voids is a predictably acceptable way of making repairs. In large areas weight and cost will chime in.

Epoxy has it's uses and limitations, so should be used wisely.

Solid timbers, that have good sized checks or other damage, would seem likely candidates for epoxy and filler at first glance. These timbers will move quite a bit with moisture content and shake out any hard clump of cured goo, packed into a crack. Worm holes can be filled very well with epoxy, but the wood must be very dry and raw. CPES and other epoxies have varying formulations to address flexibility and other issues.

You should find out what the full extent of the damage is and then evaluate some of the techniques, methods and materials you'll be required to perform.

Personally, I skip the cupernol and do the right thing for the boat, by way of a repair, in the tradition of, if not, as it was originally crafted. Your liner idea is being done a few ways, one with reinforced epoxy. Cast in place, then drilled the correct size. Some using a PVC pipe set in epoxy or 3M5200 (neither idea I like because of the properties of PVC and the limited stick epoxy and 5200 have on it) Also available are engineered assemblies that produce a dripless, watertight seal for your rudder shaft.

First, you need to find out what the damage is (all of it) then a budget and with these tasks solved, the techniques, methods and materials generally fall into line, for several reasons, like cost, effort, skill level(s), time, familiarity with tools and techniques, etc.

[gonzo]

The main failure with epoxy "repairs" is that all they do is make a hard clump of the rot. The interface between the clump and wood is deteriorated wood, so it is not structurally sound. For cosmetic repairs it is OK.