Author Topic: True power of fabric backings test-a-long  (Read 3211 times)

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Offline sleek

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True power of fabric backings test-a-long
« on: November 27, 2013, 08:31:38 pm »
Often times we see threads on here that question the usefulness of various fabrics as a backing. My take has been for quite sometime now that the idea of a single layer of fabric working as a backing is bunk. This conclusion I have come to as a result of many single backing failures I have experienced. I have tried silk, and canvas. It has been told to me recently that at least 3 layers were needed. This may be true. Question is, how do we know? Folks list bows they have made with layers of fabric as evidence, but without taking the backing off and testing the bow, we never know if it was needed at all. Aside from that, I think 3 layers of fabric is an insane amount of weight/work in the form of glue and fabric. But that is my opnion only and wont let that affect my tests here.

Instead of a woven fabric I have advocated the usage of the single strands laid down and applied like sinew. This is a method I have tried twice in the past with extream success. To the point of destroying the bow I tested both repairs on separate bows. Both broke in different locations than the original break when tested to the extremes.

As my test subject I have an Osage bow that broke because I did an especially stupid thing. I heated the bow in a weak spot to stiffen it, then braced it without allowing it to normalize. It broke while bracing. This bow had been pulled back at least 100 times before this happened. So as a side note, let your bows normalize in humidity before attempting a bend.

I will be doing several different styes of backing assuming the bow holds through each one. The most sure ones will be done first then the more risky backins done last, until the bow is finally broken all the way. Then I will show how to cut a bad limb off and splice in a new one. Last part will take a while as at the moment I dont have a proper bit of wood for a new limb.

PLEASE NOTE! This is not me showing how to repair a bow. In my opinion, this is not a safe way to do things, and a bow once broken shouldnt ever be trusted. Especially in the hands of others. It is only to show the power of various backings and styles.

Here is the Osage break in the limb inside the inner 1/3, where the most stress accumulates. Because it didnt break at draw the belly stayed intact, and I can do this. Also, the belly has no set or chrysels to deal with. Got lucky on it for this purpose. Right now the splits are impregnated with TBIII and clamped up drying. It will be a day before I take them off to apply the backing tests.





Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline bubbles

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Re: True power of fabric backings test-a-long
« Reply #1 on: November 27, 2013, 09:02:13 pm »
Sweet. I'm excited for the results!

Offline wood_bandit 99

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Re: True power of fabric backings test-a-long
« Reply #2 on: November 27, 2013, 09:08:10 pm »
What backings are you using? I am excited, should be very interesting
"Judge a man by his questions, not his answers" ~Anonymous

   "The person who says it cannot be done should not interrupt the person who is doing it." ~Chinese Proverb

Offline Dan K

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Re: True power of fabric backings test-a-long
« Reply #3 on: November 27, 2013, 09:59:03 pm »
I'll be following this one for sure.
Excellence is a state of mind.  Whether you think you can or can't...you're right!

Offline vinemaplebows

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Re: True power of fabric backings test-a-long
« Reply #4 on: November 27, 2013, 10:47:54 pm »
Interesting, I have my belief backings have merit....guess we will see.
Debating is an intellectual exchange of differing views...with no winners.

Offline dwardo

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Re: True power of fabric backings test-a-long
« Reply #5 on: November 28, 2013, 09:52:03 am »
Might be getting the wrong end of the stick mate O:)
But, will this not just prove how good your glue in the limb is? The only thorough test I can think of is exact dimensions of wood samples back with different materials, then tested to destruction and see which one gives out first.


Offline Slackbunny

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Re: True power of fabric backings test-a-long
« Reply #6 on: November 28, 2013, 03:20:44 pm »
Might be getting the wrong end of the stick mate O:)
But, will this not just prove how good your glue in the limb is? The only thorough test I can think of is exact dimensions of wood samples back with different materials, then tested to destruction and see which one gives out first.

You would also need multiple specimens of each combination. For instance you couldn't just test one each of oak backed with linen, silk, cotton, and rawhide. You would want at least five samples of each combo, and then average the results. This would ensure that the individual characteristics of each piece of wood didn't skew the results. The more samples, the better.

Offline tattoo dave

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Re: True power of fabric backings test-a-long
« Reply #7 on: November 28, 2013, 03:41:12 pm »
Cool test. Looking forward to seeing your results. I once broke an ash molly bow. The bottom limb broke, patched it, then the top limb proceeded to break. >:( Anyway, just for the sake of experimentation, I wrapped the entire working limbs in epoxy soaked cotton fabric. Took a lot of set, but, it's still shooting to this day. I called it the broke joke. Hunted with it last year. Good luck.

Tattoo Dave
Rockford, MI

Offline lostarrow

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Re: True power of fabric backings test-a-long
« Reply #8 on: November 28, 2013, 04:19:10 pm »
IMHO the backing only serves to protect a soft wood and to help a less than perfect back from raising splinters. Not really expected to save a doomed bow. Good luck with the experiment! Interrested in the findings and the ensuing ,proverbial "can of worms" ;).

Wish I had put a backing on that last Elm bow that was  shot in and almost finished ,when I dropeed the clamp on the back >:(

Offline sleek

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Re: True power of fabric backings test-a-long
« Reply #9 on: November 30, 2013, 03:17:39 pm »
The first test on this was to test the glue joint itself, to make sure the glue joint wasnt doing all the work. It broke half way to brace. Now to reglue, and wait again for it to dry.

Reading some of the replies I can see that I will not be able to please everybody. But I am going to go through these test anyway. Take from them what you want. When I am done, if the bow survives, I will see about doing other material on request.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline vinemaplebows

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Re: True power of fabric backings test-a-long
« Reply #10 on: November 30, 2013, 05:02:17 pm »
I applaud your efforts either way, you will always have doubters....that's the nature of the beast. :)
Debating is an intellectual exchange of differing views...with no winners.

Offline DuBois

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Re: True power of fabric backings test-a-long
« Reply #11 on: November 30, 2013, 07:32:57 pm »
I like it. I think it's cool to see what can be done with a fractured bow. Even if it's not perfectly scientific, it should holds some merit if a backing keeps it together. IMO
Anyways, it's fun to %$@^ around with and see what happens right?  >:D ;)
I for one want to see it.

Offline Slackbunny

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Re: True power of fabric backings test-a-long
« Reply #12 on: December 01, 2013, 10:32:03 am »
I think its still a valuable test. We'll still learn from it, and I imagine you'll have a good time doing it.

 I was only commenting on what you'd need for a truly comprehensive test. I didn't mean to discourage you.