Help, rot

[BWD]

I have a rot problem with an 18 foot outrigger canoe build, detailed below, copied from original thread under multis. I would be very grateful for any advice.

Originally Posted by BWD

An update and a question:
After much thought and fiddling with hull shape in CAD and some models I went with Dierking's advice and used WRC instead of tortured ply. Construction is 1/4 WRC strips sheathed in 9oz 8HS S-2, epoxy. Maybe overkill on the FG but I plan for hard use and "analysis" showed I would never break 50# without giving up a lot of strength, plus the glass was on sale.

Built upside down over male molds, glassed outside and flipped to find there are spots on the garboard/keel strips! (unfortunately I made these of Douglas Fir of less than prime quality -thought it was good enough ) Spots are scattered, gray, and soft to poking with needle/razor. ROT! Pics below. And I built inside my heated home! The problem, I guess besides the poor strips, is that I had it sitting with the bottom glassed for over a week before I could flip it. Lessons learned.

Now the question. How to fix it? I have thought of:
1. Carve out and replace the strips. It's just the keel, no big deal. Might be doable because there is 18oz of s-2 glass over the middle 6" of the bottom.

2. Carve out and fill the rotty spots, pretend it did not happen. -not optimal.

3. 2. plus some kind of anti-rot treatment before glassing inside.

4. Cut him down the middle, replace keel, put back together. Sounds absurd, but would at least make it easy to glass the inside of this narrow, deep canoe.

Thanks to all who care to help an amateur!

Again, thanks. Any constructive advice very much appreciated. I am hating this as I put a bit of effort into the 18 foot rolling bevel!
-BWD

[longliner45]

could this be a fungus, or mold causing it?

[hansp77]

From what you have posted it really doesn't look too bad.

I am no expert by any means, but if what you have posted is as bad as it gets- I would probably go with option 2 and 3-
just try to cut out the affected wood, maybe with something like a router, treat what remains (with some sort of rot inhibiting product- in my country we have a now banned copper based product called Blue7), thouroughly clean the wood of this residue, and either splice in some new wood peices with epoxy (with the right alignment of grain), or just fill with epoxy and glass fiber.
Of course going with this solution, depending on how much you would have to do could end up as just as much or more work as replacing the whole lot.
If you are definately going to do something, I would investigate with some cutting and digging and see how far the rot goes in, then make your decision.

I could of course be wrong here.

Good luck,
let us know how it goes.

Hans.

[BWD]

Thanks for the replies. It looks like the rot is only surface to some fraction of a mm -that's all I can see with a 4x loupe. Not really up for microscopy and special techniques, but the problem is the darned microscopic aspect of it -filaments, spores.... Really maybe I am ok, it did just happen in a short time and it is limited to scattered spots. I am thinking of digging out a margin around the spots and filling with bog. Might also route through to outer skin at intervals and pour little dams to prevent spread - used fir for this part more for its strength during the build than when complete, keel area will have 18 oz S2 inside and out when done.
Can anyone recommend a good anti-rot treatment available in US to go under the epoxy? (Have been using West for fillets etc, S3 silvertip for glass).
Thanks again!

[Ike]

BWD, take a look at this thread on the Woodenboat forum about Douglas Fir. What tou have may not be rot. http://www.woodenboatvb.com/vbulleti...ad.php?t=60734

You might be able to easily rid the wood of this.

[BWD]

Thanks for the reference, Ike.
I am thinking it is a mold, mildew-like in its appearance. Not sure if it is really wood destroying. I guess I could hose it down and wait a few months to see...
...but I am thinking I will just carve out the spots, treat as rot with EG and borates, fill with epoxy and get on with it. Maybe unneeded but it shouldn't cost too much or take as long as replacement. And next time I build this way I will precoat the inner face of the planks.
-BWD