Primitive Archer
Main Discussion Area => Bows => Topic started by: swimbill on October 13, 2012, 12:04:57 pm
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After having several delaminations using TB3 I am looking for another option. I am planning on building a trilam with Ipe and Hickory. I have a local marine store selling West System 2 part epoxy that looks like it would do the trick. However it is really expensive ($40/quart each part). Does anyone have experience with this adhesive.
Any advice is welcome
Swimbill
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I've worked with epoxy, this stuff dries super hard and strong, like a plastic. It cracks if it is bent too far from my experiences, I would be careful.
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WEST boat epoxy isn't really designed for laminating although you can add fillers to it to bulk it up so that it isn't as runny.
A boat building shop usually will sell the actual laminating epoxies from various companies. Look for WEST G flex or System 3 T-88 or G2.
WEST also makes a cartridge of Epoxy called 610. It's very good stuff too.
All of these epoxies are excellent for bows and only need room temp to cure.
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Do you know why your bows delaminated? TB glues ate quite specific about surface prep and they are not gap filing glues. Both surfaces should be smooth and well mated.
I've been building wood bows for over 30 years and never had a bow delam that was glued with any of the TB glues or even Elmer's Glue-all.
Another inexpensive option is Weldwood Plastic Resin. It is a urea glue like Urac and comes in powder form that you mix with water. A few years ago I bought a 1# bucket of it for a little over $5 from Ace Hardware.
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+1 on the weldwood plastic resin. Good stuff.
Russ
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Does the weldwood fill gaps? Or does it prefer flat surfaces like TB?
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If you are having trouble with TB3 try being easier on clamp pressure. If the pieces are well mated and clean you do not need all that much pressure. Try buying some new glue. If it ever got frozen, it is garbage
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i know some bowyers that make trilams of ipe and hickory and bamboo.they all use smooth-on epoxy.you can get it at three rivers.they swear by it.hope this helps.
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If you have problems with delamination with TBIII your problem is almost certainly with the fit of your boards or clamping method. The gluebond is generally stronger than the wood itself. I've not worked with Ipe, but many tropicals are oily and need special treatment,even if you are using epoxy.What do you use to clamp?
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I use tradesman style clamps about every 6 inches, the only time tb3 has failed is with the Ipe it worked on every other type of wood I have used. The surfaces were perfectly flat having run the boards throu my surface planer to get a good fit. I think I will give one of the other glues a try
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Ipe is oily wood. Probably why it didnt old. I used URAC on the two.....or three??? BBI's I made. Worked great. Smooth on would be a fairly close replacement, probably better. You may be able to find URAC still for sale.
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Are you using a pressure strip between the clamps and the glue-up? If not you might inadvertantly be adding more pressure at the clamps and not enough between the clamps. What you want is even pressure throughout the entire length of the glued up bow.
Any and all of the glues mentioned above will successfully laminate wood if done according to the glue's specific instructions. Each one is different but the bond of each one is stronger than the wood you are glueing.
I have successfully glued both hickory and bamboo backings to osage, ipe, locust, hickory, yew and hickory backings to many other belly woods with TB glues and never had a delamination.
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I agree with Pat. probably the uneven clamp presure. Even it out with cauls in the shape of the bow you want to wind up with or if you are looking for a straight stave you can just use straight boards obviously. I'm sure if you do a search there will be gobs of info on cauls and clamping on this site.
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try using 10 speed bike inner tubes for clamps.don't split the tubes,just cut the tube so it is still a tube.if you split it,it will be too thin and tear.two tubes will be long enough to wrap a bow.