Adhesives for laminating stems

[alick burt]

I am currently in the process of making my first woodstrip canoe using ted moores excellent book as my guide. I have just steam bent the parts for my stems and am finding it difficult to get a large enough quantity of epoxy glue for them (in the uk)without resorting to buying lots of small tubes at vast expense!
I can however get hold of cascophen boat building glue(I think this is a phenolic resin,its the stuff with red liquid and a white powder hardner) and polyurethane adhesives of the fast setting foaming variety.Would these be just as good or have I got to keep hunting for the elusive epoxy?

[mtpocket]

alick burt,

Welcome aboard

I used epoxy to laminate the stems on my boat then started finding many posts by other builders that used wood glue. The common thinking is that the stems are going to be totally covered with epoxy later during the glassing phase so they should be fine.

[ealger]

alick burt
Regarding epoxy, if you plan to glass your hull, you're going to need epoxy eventually anyway.
The polyurethanes are too miserable to work with, in my opinion. Even yellow glues set up too fast when having to spread over 8 or 10 laminations.
I'm not familiar with the cascophen you mentioned, but consider the color of the dried adhesive which may contrast with the material you are using for the stems. (This is not a big deal, but the purist would complain! :eyebrows

Which ever adhesive you use, I would look for a slow setting type. I guess that's why thickened epoxy is the choice.
Ed..

[KARKAUAI]

Ed's right, get your epoxy for glassing the hull, mix small batches and thicken with wood dust from sanding (not sawdust) to the desired consistency and color and glue with that. No need to buy more epoxy, you should have plenty. The color is often darker than you want and can be lightened farther with ordinary flour; make your glue lines the same color or darker than the wood, lighter shows up more and doesn't look as good.

[Doug]

Make it four, for epoxy.
Your stems is one of the most important structural parts of your canoe.
Go all out, even if it is over kill.

Doug



.

[alick burt]

Thanks guys you've convinced me epoxy is the way to go.This has led me to a couple more questions.
Is the mix ratio to be the same as that I would use to skin the boat with or do I make it a different amount of hardner to adhesive?
If I add wooddust to it will this affect the strength and how much should I add?
Many Thanks
Alick Burt

[Erik, Belgium]

I agree that epoxy is best to glue the laminated stems, BUT I personally didn't do it that way on my Winisk. I just used yellow PU glue (outdoor quality) and the laminations held up perfectly. Make sure that you let it soak in for about 5 minutes before joining the pieces, just as you would do when using epoxy.
more info on my Winisk http://users.pandora.be/kano-kayak/Winisk-1.htm

Sorry to be some kind of outlaw against epoxy usage here, but also for laminating my paddles (so far more then 10 canoe and Greenland paddles), I have used the same PU glue without a failure. Finished most of them with oil (only 2 of them where varnished) without any problem after 3 to 4 years intensive use (3 times a week).

The only time I had a bottom piece of reinforcement on the blade coming loose with PU glue was, when I forced a piece of purpleheart to bend by clamping only. I guess I may have driven all PU glue out while clamping to hard.

When using thickened epoxy, the "glue force" does weaken by mixing it up with silica, milled cotton or sanding dust.

I understand that epoxy is widely used for bonding in canoe- and kayakbuilding in the States, but my personal opinion is that it is not always necessary.

Sorry,
Erik (the outlaw from now on ?), Belgium.

[hoz]

I used regular elmers carpenter glue for my stems. No muss or fuss.The stems were covered with bias cut F/G. My canoe is 6 years old this winter and there have been no problems with delamination.

[ealger]

I would suppose that the number of stem laminations can vary from 1 to 6, or more. If one were gluing up just say an inner 3 lamination stem, then perhaps one of the capenter glues would work. So one could glue up the inner stem and let it dry. Then add on the outer stem pieces (not glueing the outer to inner stem parts!) and let it set.

The Aliphatic based glues, we have in the U.S. want to be clamped as soon as possible. These glues, spread to a resonably thin thickness, will skin over rather quickly. This is not a good condition for making an integral part of a boat, IMHO.
I've been glueing up furniture for 45 years and the older I get the more time I need
Ed...

[KARKAUAI]

If you use epoxy, mix it in the same ratio as for glassing, add enough dust to make it a glue-ike consistency.

[Patricks Dad]

Be sure the stems are completely dry (assuming you steam bent them). Apply unthickened epoxy first, let it soak in well, wipe off the excess then apply the thickened epoxy.

[Bassbug]

I found it much easier to use Gorilla glue rather than epoxy for the stem laminations. It cleans up much easier than epoxy and from my experience with the stem (and also the gunwales - you can glue with Gorilla, then steam and bend without separation - I tried this and it worked well) and the numberous laminated paddles, I have not had any failure. But if epoxy trips your stem-lamination trigger, use it!

[Erik, Belgium]

bassbug,

BI 'm surprised to read that gorilla glue holds when steaming it. Amazing !
I 've never seen Gorilla glue in Europe. Does anyone know under which brand it is sold outside the States ?

Erik, Belgium

[KARKAUAI]

Hi, Erik,
Check out this site http://www.gorillaglue.com/gluefinder.htm# . Looks like they sell it as Gorilla Glue in the UK.

[Arno photo]

Erik,
Gorilla glue is PU glue (exterior wood glue). In France it's sold as SADER brand.
Yellow carpenter's glue means "parquet" (sorry for the word in french) glue (or PVA glue) with i think alcoolic solvent.
It's difficult for the european people to find some products who seems to be really easy found in States!!!