Have some bad news. HELP please...

[evilpriest]

Hello everyone, Ive been building a 17.4 ft bill clarke design for a while now, have top coated the hull and finished most of the interior work, and have just moved up to the anchor locker and have found some bad news. Where the previous outside brass was screwed down the keelson, i removed when i first bought the boat. Now the anchor locker filled with water and was leaking out the holes, the keelson is now weakened because of the foriegn water, i can push a chisel about 6 mm into the wood with ease. Is this a major or is there anyway around it? Like putting high strength fibreglass on the inside to support or even using endurathane? Any answers would be appreciated.
Cheers

[Stumble]

Sounds like rotten wood and a pretty bad case of it. You don't desribe your access to the wooden area, but if you can get to it then just pull out the old rotten wood and if it is a small area then just use an epoxy fillet to refill the space.

If the wood is a core instead of a plank, then you will need to drill out a hole into one side large enough to remove all of the rotten wood and then do a patch job once you get the rot out and dry out any remaining wood.

[diwebb]

Hi,
the problem sounds like rot but the fact that the wood is totally saturated could be making it look worse than it really is. Some woods get very soft when totally saturated. Do you know what species the wood is?
The first thing to do is dry it out. I mean totally dry not just surface dry. Then test to see wether the wood has hardened up again. If it does not but it seems to still have some strength you could try saturating it with penetrating epoxy. If you can not get a water thin epoxy then thin with MEK until it is , usually about 15 to 25% by volume. Keep applying coat on coat until the wood will not take any more. Wait for it to dry then overcoat with a couple of coats of unthinned epoxy. This should give most of the strength back to the wood and be trouble free for the future.
If the wood is totally rotten then the only proper soulution is to cut out the rot and scarf in a new piece.
Best of luck with the project.
David.

[Stumble]

Diwebb you NEVER want to thin epoxy with solvent! Yes I know there are some really odd applications that may justify doing so, but in general it sacrifices the mechanical properties to such a degree that you might as well use bondo. Secondy when you do use a solvent any more than 5% by volume is too much, and can lead to a faulty finish product that often will never fully cure. When thinning is justified the best way is to warm the area where you will be applying the epoxy to about 140 degrees.This increase in temperature will thin the epoxy as it is applied and keeps the working pot from kicking prematurely.

However in this type of application, rebuilding a rotten bulkhead, I think a fillet would work better, but would need to see pictures of the damage first.


Check out http://www.seqair.com/skunkworks/Glu...inning.htmlfor a more detailed analysis of thinning epoxy.

[diwebb]

Hi Stumble,
I would agree with you if this was a totally structural use of epoxy, however this is to harden up some wood that has the beginnings of rot in it and I have used thinned epoxy on numerous occasions for this purpose, with good results. This is not a bulkhead but a keelson so an epoxy fillet will not work and filling with epoxy putty after removing any soft spots is not a good option either, so the best way, as I se it, is the penetrating epoxy or full replacement.
David.

[Manie B]

PHOTOS PLEASE

Then we can see whats going on

this forum can definately point you in the right direction

[Stumble]

David,

I don't disagree with you about using epoxy just the need to thin it.

I missed the part about a keelsump. But it doesn't change my answer too much. From the studys I have read there is no good reason to thin epoxy. It only marginally increases the depth of the epoxy into the substrait, and normally does nothing to increase the stength of the bond, since the wood-epoxy bond is normally stronger than the grain adhesion of the wood in the first place. Secondly a thinned epoxy coating is significantly more porus than a standard mix, meaning that for a barrier coat it takes more applicatins to get the same result.

So the only reason in this application to thin the epoxy is if you don't do a good job cleaning away all of the rotten wood. And if that is the case, you have introduced a whole host of problems, and really failed to the the proper prep work which always leads to bad results.

[PAR]

This subject has been debated and frankly, most repair experts agree, that thinned epoxy is a waste of time and money in most cases. It's not the depth of epoxy penetration that provides waterproofing, it's the solids content, which is diluted as soon as you add solvents. There are some instances where using a lighter viscosity epoxy can be helpful. To get this, it's much better to use the "hot on hot" method then to thin epoxy or buy pre-thinned epoxy. You'll find all the major epoxy formulators are in agreement on this as well. Only those selling thinned epoxy will have you believe anything other then what the tests have shown.

There is no magic goo in a can, that can restore the strength and physical properties of wood, back to rotten wood. Contrary to what advertisers might suggest, the tests are very clear.

[rfnk]

Manie
You gave us a fright with those big letters! Rick