glue failure and glue choice ?

[Jim Davis]

I have had two glue failures in the last two days.

In one case, I had glued a lamination to the face of a fade and on up the limb. It held for several hundred shots. The bow was Osage 66" ntn and shot very well at its 48#. The glue on the face of the fade let go in a flash and with a bang, destroying the limb. That gluing attempt was ill advised, because it amounted to gluing end grain on the fade. I understand that one.

The second failure was on a block added to the back of the handle. The fade was entirely on the block. I know the limb flexed too much under the lip of that block. But after I heard the crack, I checked the block and popped it right off with a chisel. The glue seems to have broken and didn't  take any wood with it on  either piece. The limb and wood were both Osage again.

The glue was Titebond II. I have not had this kind of trouble with it before.

I dampened the surfaces  before applying the glue and it all looked good after curing.

I don't want to use epoxy, because I have had worse results with it.

Is there a glue that will penetrate the wood more than Titebond does? Or can I thing the Titebond and let that soak into the wood, then glue as usual?

[George Tsoukalas]

Jim, did you follow directions on the container?
I ask because I often note people roughing the area when directions call for cleaned well sanded surfaces with good mating. Just a thought.

[RBLusthaus]

Was the bottle of glue stored in an unheated space.   I had that issue before and believe that my glue went bad due to excessive cold.  No proof, just my thought.   I keep my glue in the house now and have not had trouble since.  Russ

[Jim Davis]

surface was smooth and flat, not roughed up. Glue was also used to laminate a hickory back on the limbs of the same bow and it;s holding.

My description of the handle block location was not really clear. The block was glued on the belly side of the handle, in the usual place.

I'm thinking of making a longer block and making the fade longer so the transition is longer.

[bubby]

Sounds like it was just vending to much in the handle, is is possible that you starved the glue joint?

[PatM]

It's all about where your joints were, not the glue.

[gfugal]

It's all about where your joints were, not the glue.

This is what i was thinking. Maybe you can try feathering thinner lamanents to get your handle thickness. I think i heard someone mention this somewhere.

[vinemaplebows]

It's all about where your joints were, not the glue.

This is what i was thinking. Maybe you can try feathering thinner lamanents to get your handle thickness. I think i heard someone mention this somewhere.

Yes, this works well.

[mikekeswick]

If the handle area is too thin no glue will hold it on.
Without pictures it is all guess work though
Many epoxies have better 'numbers' than TB2 - you shouldn't be down on all epoxies! There are many,many different kinds My two favourite glues are TB3 and EA40, depending on the job at hand.

[Jim Davis]

I think Pat is onto the cause. The fade started thickening slightly after it started narrowing. I have glued on a new block that I will start the thickening a half inch or so before the limb begins to narrow toward the handle.

This is one of my take-down bows where the limb root slips into a steel sleeve. I have a half dozen of these that are performing just fine, but, as Pat  suggests, I think the geometry of the glue joint was faulty.

Thanks for all the input.

Jim

[DC]

I've had a couple of handles pop off. At first I blamed the glue. Then I realised that I was seeing lots of glue on handles. Just about every board bow made has a glue on handle. Glued with all different kinds of glue. Now maybe all these people are lying and thier handles only last long enough to take pictures but I doubt that. That's when I swallowed my pride and realised that it must be me doing something wrong. I've now got a few bows roughed out that are going to need handles. The first one I didn't clamp as tight as I was doing. It should be ready in a day or so. I use epoxy.

[Jim Davis]

Agree with just about all above. I've done a lot of glued-on handles, but didn't notice that I had the thickness taper start growing too far toward the handle.