Epoxy treatment to stabalise old wood

[alan006]

I've heard that you can get an epoxy treatment that is ideal for putting strenght and rigidity in old timbers. I've been told that its an American system and you drill lots of small holes in the timber and let the resin work its way in by capillary action.
I was wondering if anyone here has tried it and if its any good?

 

[Poignard]

CPES™ (Clear Penetrating Epoxy Sealer)?
I doubt it's much good, except as a temporary botch-up, or as a protection for the end-grain of new wood and plywood edges.
From bitter personal experience I have learnt that the only really effective long-term treatment for rotten wood is new wood.

 

[TradewindSailor]

If the wood is rotten ... putting epoxy resin in it will only provide the strength of the resin where the resin can go. The wood fibres will not provide any strength.

I would use a quality epoxy like West's to relaminate delaminated plywood where the fibres are still good ...... but I would NEVER use it to replace what should be solid timber. Cut the rot out at least 12" along the grain into good wood from the rot and replace.

If you do use this penetrating epoxy you will probably find rot beyond the epoxy penetration within 6-12 months. Strength-wise the repair will be inconsistent, unreliable, and ... yes a bodge.

 

[alan006]

Thanks for your feedback, chaps. The wood I'm thinking of treating is not rotton. The reason I am thinking of treating it is that I want to change the properties of the material.
Let me explain.. the hull planking was double diagonal and I have replaced this with tripple diagonal iroko fixed by epoxy. This will make the hull a lot more rigid than the original so to avoid a lot of movement on the interface of hull and keel I want to make the keel as ineret as possible so that avoids expansion and contraction against the epoxy hull. So, I thought about injecting the resin to meet these requirements.

 

[old_salt]

I must say after a good few years of restoring a 1905 gaffer I entirely agree with Twisterowner the only way is to replace with new wood.
It is an accepted thing in shipping (Big 'ones' as an ex merch engineer) they go into dry dock and are re-fitted this will include replacing old worn out bits, as well as up dating to new technology.
So if you are refitting a small boat there is noting wrong in replacing the worn out part with new stock.
Just sticking with a worn and damaged bit because it is original and cocking it up with a bit of 2 pack resin it not really the traditional way of doing things.
Get it right and it will last for another 100 years.

 

[alan006]

We seem to be misunderstanding each other here. Its nothing to do with bodging up rotten wood. The whole idea is to change the properties of the wood to make it ineret so as to avoid the expansion and contraction in normal wood.

 

[Sixpence]

David , put your specs on mate /forums/images/graemlins/shocked.gif the wood aint rotten /forums/images/graemlins/grin.gif

 

[Captain Coochie]

I would think by doing this you are going to stop the wood from breathing and inviting rot . Not quite sure why i think that but i do /forums/images/graemlins/confused.gif

 

[alan006]

That's a fair point, it would be a shame if I succeded in reducing the movement only to find it rotted out.
I'll have to do some experimenting before I start drilling lots of holes in my keel.
alan

 

[Peterduck]

I think that a fair bit of impartial [ie non-promoting] information needs to be sought. I've used epoxy in the saturating mode a fair bit, and I do not believe that it soaks in as far as its promoters would like it to. Certainly, some timbers are more amenable to having epoxy soak into them. Many [but not all] softwoods would be good for this, but few hardwoods would be. Timber is also much more porous along the grain than across it, hence the multitude of holes advocated for this process. Do you have a sample of the species of which your keel is made, so that you can do a test on the end-grain and the side grain? If you want to do a test before lashing out on the expensive epoxy, try using ink. Soak the end of your sample in a dish of Sheaffer's finest, and saw through the sample along the grain afterwards to see how far the ink has soaked in. It could be very illuminating.
Peter.

 

[andrewbodenham]

It won't work. Epoxy will not permerate into the keel to any significant extent, unless you riddle it with so many holes that you reduce the mechanical strength of the keel.
I think it would be better to accect that differential movement will occur, and to engineer a solution to cope with it.

 

[bluemoongaffer]

I've used CPES for treating new timber and ply prior to epoxy coating or painting. The CPES does soak in well, but not more than say 1 mm (much more on end grain). Apply several coats to let the wood become saturated. If you epoxy over it within 24 - 36 hours of putting the CPES on, you get a really good bond and a good water resistant coating, which is why I guess why you want it for your keel (which is wood, I assume). You would need to make sure that all surfaces are completely 100% clean wood and that every part has plenty of CPES and then epoxy. N.B. This scheme won't work if you can't also coat the mating surfaces between hull and keel. Also, it might be advisable to add in some glass cloth on any areas of wood that might get damaged - as soon as an epoxy coat is breached, water can get in, even if it has got CPES on it. There is lots more advice on the woodenboat forum about CPES (use google to find) - I suggest you use the search thingy on their website first rather than post a new question - otherwise you'll probably get your head bitten off. Having said all this, CPES was not easy to get hold of in the UK - I got mine from European importer, who was in Sweden. I think it's made by a company called Smiths on the West coast. Expensive stuff too. By the way it does seem to work quite well on rotten / worm wood as well. The smell is something else - you'll need an organic filter air mask. Regards

 

[Poignard]

Lot of information about the different types of epoxies and their properties on this site

Interesting to read that WEST, which originally stood for Wood Epoxy Saturation Technique, has been renamed to mean Wood Epoxy Stabilisation Technique!

BTW, I'd be very interested to know how the hull of the Jubilee Sailing Trust "Tenacious", which was built of epoxy "saturated" wood, has lasted compared with her steel stablemate "Lord Nelson". Anybody here involved in maintaining her hull?

 

[alan006]

Re Peterduck

We are thinking along the same lines. I was going to get a piece of timber identical to the keel, and drill holes at varying distances apart and then when the epoxy has gone off saw the timber up ( at different distances away from the holes). This should show two things a) if it penetrates properly and b) if it does how far apart the holes have to be to give complete coverage.
The offcuts could be left exposed to see how they weather over the next 2 years ( which is how long it will take me to finish the tripple diagonal planking on the port side).
I'll then have an idea as to if this is a goer or not.
alan

 

[LittleShip]

CPES is great for protecting wood from water ingress and as such only needs to penetrate a few mm, it isn't designed to add strength to the timber.

There is a web site called the Rot Doctor which explains how he uses this product on a 100 year old boat
http://www.rotdoctor.com/

Good product if used correctly and the correct use is to keep water out!

Tom

 

[Poignard]

The downside is that anything that keeps water out will also keep it in, so any damage to the epoxy coating has to be quickly spotted and repaired.

 

[LittleShip]

Yep agree with that statement.......... but it is great if used when replacing "new" wood, pity we dont have it in the UK ! or do we??

 

[johnchampion]

I tried to get some CPES a couple of years ago but failed as the only outlet I found was in the US and it's a hazardous material to ship. I understood however that it was best used on rotten wood as a wood hardener where it was able to soak in because the wood was rotten. Good wood is much more impermeable and it won't sink in very far.
I spoke to the guy who makes/sells it in the US and he said that while there was nothing else like it(well he would wouldn't he) that the real secret was that it was slow curing which was the reasonn it could soak in.
He suggested that I could try West System epoxy mixed with 15% xylene which would slow down West and also make it thinner to give it a chance to saturate the rot. West of course strongly say don't mix there product with anything. I did buy some xylene but that's still languishing in the garage as I lost interest as I could not persuade myself any of the stuff would have a lasting effect - so I reverted to the norm and chopped the rotten bit out.

 

[Peterduck]

Sounds sensible to me. Best wishes for success.
Peter.

 

[roly_voya]

The traditional way that they keel is kept from moving is the strength in the floors not in the keel. On a modern canoe boady/fin keel it is the keel root (but this is always a week point) If you ar stifening and strengthening the hull but not the frames, floors, stem & stern post and other ellements of the boats structure you might be setting up stress concentration points and be in for some sevearly leeking garboards. Can you run the idea part a disiner or experienced builder to check for potential problems?