Glues for graving

[Richard_Blake]

Right, it's this traditionally planked wooden boat, with dodgy fastenings here and there, and too many butt joints. Planking (1.5 inch larch) in general very good apart from deterioration around fastenings. I need to put in graving pieces where the crumbly bits are, then adding new screws. All no problem so far.
I also want, where butt joints proliferate, to rout out half the depth of the plank out to the next frame each side, and glue in a socking great graving piece (in effect a half-thickness plank about 3 feet long) which will replace the bad bits and turn the two planks butting into one long one (a slab scarf). I've no problem with the technique or execution - it's been done before in restorations - but WHICH GLUE? Epoxy fills the gaps in my joinery beautifully, which resorcinol would not - and I'm gluing blind, as it were, on the boat, and can't see the back face or glue edge. Will epoxy be too much of a moisture barrier half-way-through as the plank swells and contracts? I've heard of something called perhaps Balcotran moisture-curing glue - which I gather might allow long-term slow moisture penetration. Does anyone know it? Does it fill gaps? Could I get it in the Netherlands? What's the chemistry involved?

All thoughts gratefully appreciated

Richard

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[Peterduck]

Go with the epoxy; I find it the most forgiving of any discrepancies in fit. and it does not require the enormous pressure which resorcinol does. My experience with polyurethane glues [e.g. Balcotan] is not encouraging. I would not use it for anything which I had to rely on. As a backup to proper fastenings, OK, but by itself, I wouldn't use it.
Peter.

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[Mirelle]

I agree entirely. My boat has several graving pieces glued in with epoxy following damage in the October 87 hurricane, and frankly I had forgotten they were there until I burned her off two years ago. I have now lost track of them again! The planking is teak, so this is a fair test of a glue, I think.

Moisture will migrate along the grain (as the Almighty intended!) much faster than across it.

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[Richard_Blake]

Thanks to both for setting my mind at rest. I shall get on and enjoy the job! be back with lots more questions over the next couple of months, I expect.
All the best
Richard

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[oldsaltoz]

G'day Richard,

For a good strong bond, you can thin the epoxy with meths and let it soak in, thus reducing future moisture at the interface, after ensuring the timber is very dry (and oil free) first, a light sand after it sets and you are ready to glue, knowing you have a sound base;, mixing some fibres with the glue coat will also help provide an excellent bond.

I hope this helps. . . . . .

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[Richard_Blake]

Thanks, Brian. Good tips.

R.

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