Sealing teak. HOW?

Scotty_Tradewind

Scotty_Tradewind

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I've put a new grp deck on after getting rid of the teak but have a saloon or doghouse made of teak.

I still have a small amount of water seeping through the teak saloon sides in a couple of places when either the weather is very wet or in lumpy conditions. I cannot yet isolate the exact points of ingress. I may have to resort to vegetable dye in water etc... in areas to confirm.

I thought about painting many coats of silicone onto the teak.... (the stuff I used to injection waterproof a house i had years ago which worked a treat.)

What thoughts?
S.
 
If you wish to keep 'varnished teak' looks: laminate on one-two layers of thin fiberglass cloth (about 100 g/m - gram/square meter, not heavier) in two-part polyurethane varnish. One layer will not show really, looks like just varnished.
Needs care in application, as any laminating on wood, same way as with WEST EPOXY, for instance. Degrease wood first, sand a bit rough, degrease again, start with thinned varnish, put the fabric on, paint generously so all is thoroughly wetted, no air bubbles.
This is much better then laminating with GRP (polyester resin) as adhere better; or then epoxy - varnish is UV resistant, epoxy not.

Otherwise - for wooden decks people here use alkyd type oil varnish, Cetol - seals very small cracks and such, as it leaves this resin in, which is elastic for long time, gummy. Any other alkyd varnish will work, just make sure it's alkyd+oil and not much else in it.
http://www.yachtpaint.com/LiteratureCentre/cetol_marine_ap_eng.pdf
 
Scotty_Tradewind said:
I've put a new grp deck on after getting rid of the teak but have a saloon or doghouse made of teak.

I still have a small amount of water seeping through the teak saloon sides in a couple of places when either the weather is very wet or in lumpy conditions. I cannot yet isolate the exact points of ingress. I may have to resort to vegetable dye in water etc... in areas to confirm.

I thought about painting many coats of silicone onto the teak.... (the stuff I used to injection waterproof a house i had years ago which worked a treat.)

What thoughts?
S.
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The fact that it is teak is largely irrelevant. The water will not be coming through the wood but through the failed glue joints. Almost impossible to stop unless you take the structure apart, dry and reglue. You might have luck with Captain Tolleys but the basic problem is that the faces of the joints are almost impossible to get clean enough for any adhesive to fill the gap.
 
thanks so far everyone.
Tranona has suggested what I've been fearing.. a Twister owner took the whole of his saloon top off to retimber some areas to make joints good.
However, I'm hoping that I can still find some form of 'glupe' to paint on and run into the joints/seams/passageways that the leaks take.

One problem with putting on a non flexing coating of any sort is that an old boat of our type will flex so the problem may soon return if coatings of glass cloth and epoxy were applied and I'm always nervous about moisture getting back in behind the glass.

If I thought it worth it I may have sourced a grp saloon top as fitted to the later Tradewinds (the moulds are still in existance) but when boats reach a certain age and value, (and the owner gets past it!) it's a case of 'cutting ones cloth' so to speak.
S.
 
Scotty_Tradewind said:
However, I'm hoping that I can still find some form of 'glupe' to paint on and run into the joints/seams/passageways that the leaks take.

One problem with putting on a non flexing coating of any sort is that an old boat of our type will flex so the problem may soon return if coatings of glass cloth and epoxy were applied and I'm always nervous about moisture getting back in behind the glass.

when boats reach a certain age and value, it's a case of 'cutting ones cloth' so to speak.
S.
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Actually there are some. :)
First is this reinforced varnish method I've given - polyurethane is not so thick a resin as epoxy or polyester, so penetrates better. You may start with couple of very thinned layers. This was used on boats built with thin strip planking, not glued, only nailed together. No seal in the seams, so old boats were getting leaky. Polyurethane resin getting into glued them together and glass cloth kept it less movable, so to say, stiffer. As with varnish generally, this kept for maybe 10 years max (longer then normal varnishing, but not permanent as typical laminate), for permanent job it was made as laminate, several layers. With teak may be problem as this is oily wood, and no way to degrease inside crevices, so varnish may penetrate inside of them but not stick to the wood there. Anyway this is a layer of laminate, so will stop water.

Another way - a gluing resin, Vinacet (this is a name here) - PVA, polyvinyl acetate. http://en.wikipedia.org/wiki/Polyvinyl_acetate
Typical wood glue, but glues almost to anything. Can be had in water as emulsion, this is common form. But for such you need this in clear form (no water or additives in) thinned with alcohol. Alcohol can be added in any proportion you want, resin dissolves in it. PVA looks like clear silicone rubber and is as elastic, only it glues to wood and to any other glue that may be present in joints; alcohol helps it penetrate and get into oily wood, evaporates quickly. Then the resin sets, also quickly. And now you have joints glues and sealed with elastic rubber. So you may paint with it in suspect places; any excess can be wiped off with cloth wet with alcohol or even just water, before glue sets. It's clear so no stains and such, but as it's gummy should not be left thick on surface because varnish may later crack if painted on it.
 
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Tranona has displayed his usual talent for hitting the nail squarely on the head.

I had a crack right (a shake) right through the mahogany coach roof coaming on my Twister, which was leaking. As a temporary expedient I ran some Captain Tolley's Creeping Crack cure into the crack, pending the insertion of a wooden spline. That 'temporary expedient' has lasted nearly 10 years and still it does not leak! I also cured a leak around a car window with it.

The traditional method for tracking leaks is to use purple meths because it dries quickly and does not wet the timber.
 
Captain Tolleys is acrylic resin IIRC . So no problems, can be painted over. But naturally you will have wood impregnated with acrylic, oils may not soak in. Not that I have experience with it on wood.

But then must add - acrylic is not that elastic, or glueing itself. On cracks will be very good, like 1 mm, but on moving joints, wider, may not work. Nothing wrong with trying, you will not do anything wrong to your deckhouse.

Coelan (then again If I Recall Correctly, check yourself on the net) is just another polyurethane varnish.
After you will get sober from inhaling all those benzenes and aromatic (nice word) solvents, you will be left with polyurethane on wood, that cracks and falls out from any place any water entered and wood got wet.
In case you are not going polyurethane way - nothing wrong with this approach btw, but polyurethane gives no protection to the wood as such, just covers it - I personally prefer oil based coverings. This Cetol - also good german stuff - and generally oil based varnishes. Quite simply oil and water don't mix.

BTW: all those fancy brand names people devise for selling just few kinds of chemicals :D
 
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Scotty_Tradewind said:
Hi Parsifal HNY to all :)
this new layout wouldn't allow me to 'reply with quote'..... do you think the Captain Tolleys' would be able to be used around all the suspect places and then do a good job with Coelan after or does Captain Tolleys' start rejecting finishes in any way??
S.
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I refer my honourable friend to the excellent answer given by Rossynant. I think he knows a lot more about it than I do.

(HNY to you too)
 
I would be wary of using Coelan. It is a "marmite" product. Some people have success with it, particularly on new build but it is very expensive, difficult to apply properly, but worst perhaps if it fails it is a devil to remove. In theory it flexes and seals, but if the film does break it loses adhesion in patches.

If it were my boat I would go down the Capt Tolleys route and refinish in International Woodskin which seems to be the latest version of Cetol. If you are not bothered about showing off your lovely teak then Sikkens Novatec/Top is also good but has a matt tint.

BTW you might find your leaks are where the timber joins the deck as is common on Twisters as you know and attention to sealing that area better externally might be worth exploring.
 
Tranona said:
BTW you might find your leaks are where the timber joins the deck as is common on Twisters as you know and attention to sealing that area better externally might be worth exploring.
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Hi Tranona,
after redoing her deck in grp we then put a teak quadrant with lots of sealant between it and the teak saloon sides. Therefore I'm hoping that the ingress is between the solid teak and its own joins .... which are numerous.
Saloon sides are solid planked teak with the grp deck having a good upturn inside.
thanks for your input
S.
 
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