Author Topic: Delamination of horn overlays.  (Read 6660 times)

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Offline RickyScull

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Delamination of horn overlays.
« on: January 12, 2022, 10:05:04 pm »
Is there an adhesive that will hold better than loctites two part epoxy. Surfaces are flat and mate up good but when I brace the bow the epoxy starts to crack and gives way soon after. First time was spectacularly violent. Second time on the other nock I heard it before it let loose and I used the bandsaw to remove it. The bow is bamboo backed ipe.

bownarra

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Re: Delamination of horn overlays.
« Reply #1 on: January 13, 2022, 04:04:36 am »
A good quality superglue.

Offline Del the cat

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    • Derek Hutchison Native Wood Self Bows
Re: Delamination of horn overlays.
« Reply #2 on: January 13, 2022, 04:14:42 am »
That's possibly why warbows tend to have horn nocks which go right round the tip, they will hold on with no glue at all!
Here's a pic showing a cross section of a well fitted one (mine) and two hideous ones (which still held up).
Here's a link showing a video from my Youtube channel showing how I do it.
https://www.youtube.com/watch?v=k1VHUkDEGJA&list=PLBz2tD9476KQFyMBLEylQGh952tBT_mZB&index=9
Del
Health warning, these posts may contain traces of nut.

Offline RickyScull

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Re: Delamination of horn overlays.
« Reply #3 on: January 13, 2022, 08:03:04 am »
Awesome! Thanks Del. I will try this instead of overlays.

bownarra

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Re: Delamination of horn overlays.
« Reply #4 on: January 18, 2022, 03:39:38 am »
Overlays will work just fine if they are glued on right! It doesn't matter what draw weight. Horn nocks were 'invented' to stop the string digging into yew. If using a harder wood you could use self nocks with no problem.

Offline RickyScull

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Re: Delamination of horn overlays.
« Reply #5 on: January 18, 2022, 04:40:22 pm »
Bownarra ok. I thought they should work but the epoxy kept breaking loose. The surfaces are flat and mate up well. I used acetone on the ipe hoping that would help the bond.

bownarra

  • Guest
Re: Delamination of horn overlays.
« Reply #6 on: January 19, 2022, 01:41:33 am »
Never try to degrease wood...you only end up pulling more oils to the surface. Any good epoxy won't be troubled by oily wood. Same with superglue. I've glued directly to ipe, no degreasing, more times than I care to remember - save the acetone for something else!

Offline JNystrom

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Re: Delamination of horn overlays.
« Reply #7 on: January 22, 2022, 07:43:34 am »
I see you haven't used hideglue for gluing oily ipe... Oven cleaner allows you to actually shoot the bow and not gather splinters from your surroundings. I can't see a reason why risk with epoxies either? Delaminations happen all the time even with the best modern glues. Acetone doesn't work but oven cleaner foam does.

I also had some problems with maple 135# maple longbow and horn overlays. The wood is so soft that it somehow deforms under the horn??? Anyways, as shown with Del's good images, the english horn tip was developed into really dummy proof solution.
I have a 140# osage bow with selfnocks, just a simple sidenock. Works fine when the wood is hard. Bamboo-ipe would work fine also with selfnocks.