Author Topic: sinew backing question  (Read 5908 times)

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Offline hook

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sinew backing question
« on: December 22, 2010, 10:08:14 am »
when my sinew backed hickory broke I didnt want to waste my sinew so i peeled it off.
It came off quite easily once i got and end started and pulled. is this normal for it to come off easy or did i just have a bad glue job?

Offline Pappy

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Re: sinew backing question
« Reply #1 on: December 22, 2010, 11:12:43 am »
It shouldn't have come off easy unless you wet it,I would say bad glue. :) I have tried to get some off before without wetting it and pulled up splinters. :)
   Pappy
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Offline crooketarrow

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Re: sinew backing question
« Reply #2 on: December 22, 2010, 11:46:55 am »
   It differently shouldn't have came off easy. Unless like pappy said wet it. Warm water works best.
DEAD IS DEAD NO MATTER HOW FAST YOUR ARROW GETS THERE
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Offline gstoneberg

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Re: sinew backing question
« Reply #3 on: December 22, 2010, 11:47:50 am »
I'm trying to imagine why a tough bow wood like hickory, especially when backed with sinew, would break??  :o  How long did the sinew cure before the bow was flexed?  Maybe it just wasn't done drying?  Did you use hide glue?  If there's another thread where you answered all those questions, I apologize...I must've missed it.

George
St Paul, TX

Offline hook

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Re: sinew backing question
« Reply #4 on: December 22, 2010, 01:24:11 pm »
gstonegerg,
the bow broke because it was my 1st attempt at a bow, i pulled it back while it was still green and bent the wood. I was just hoping the sinew would have kept it in one piece. I was expecting it. it was more like a ...hold my beer and watch this kinda thing!!

Offline hook

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Re: sinew backing question
« Reply #5 on: December 22, 2010, 01:29:17 pm »
to further clarify I did used hide glue and sinew from 3 rivers however i did not clean the back of the bow before applying. I did size the bow and let it sit for 24 hrs and then started glueing, it was a little cold in the garage and i would say that the wood was about 45-50 degrees and there was some gelling of the glue rather quickly. I'd say all that added up to a bad glue job!!!! ....stupid beer!

Offline gstoneberg

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Re: sinew backing question
« Reply #6 on: December 22, 2010, 01:44:30 pm »
I see, sounds like you're right.  I've never tried to put on sinew when it's cold...or even cool.  I used to do it in the basement when I lived up north when it was cold outside...right next to the furnace. ;D  Check the build-alongs on here, I know there's some on sinew backing.  Like Pappy said, once that's stuff's glued down it'll tear out the wood if you try to pull it off without soaking it.  It takes a long time to dry too.  I have never had a sinew backed bow break...oops, hope Murphy didn't hear that.  ;)  Good luck on your next bow.

George
St Paul, TX

Offline JW_Halverson

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Re: sinew backing question
« Reply #7 on: December 22, 2010, 11:45:45 pm »
I once had an Epic Failure of a sinew backed osage bow.  But it was a bad piece of osage, it delaminated between two growth rings and when I pulled things apart, there was no way to get the sinew off the wood! 

If you sinew in the kitchen, let a dog in there afterwards to lick up all the stuff that hits the floor.  My dog LOOOOVES it.  You never saw a floor shine like this, I tell ya.
Guns have triggers. Bicycles have wheels. Trees and bows have wooden limbs.

Offline hook

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Re: sinew backing question
« Reply #8 on: December 23, 2010, 09:18:09 am »
well, at least I can re-use it and I have learned something!

Offline gstoneberg

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Re: sinew backing question
« Reply #9 on: December 23, 2010, 09:41:57 am »
Yes, each bow teaches you something.  I can say from experience that you should never sinew back a bow that looks like it will fail.  Take your bow past getting a string on it at brace and get the limbs bending a little before you sinew back.  If you discover a problem up to that point, start a new bow.  If all looks good, do any recurving or other bending with heat you need/want to do and then sinew back.  Depending on the humidity, let the sinew dry 2-4 weeks for 2 layers, more if you've done a heavier sinew backing.  Finish your tillering and shoot your bow.  Don't put a finish or covering on the sinew until you've shot it quite a bit.  If you get a failure at that point you can soak the sinew off and reuse it.  Once it has a finish applied (unless you use snakeskin with hide glue) it will probably not be possible to reuse the sinew. 

JW, up north I had a terrible time with mice getting into my dried deer tendons.  When we moved out and packed up the basement I found tendons everywhere they had drug off.  I think all animals that like to chew go after sinew.  I'm sure I lost tendons when the mice drug them down to where the dog could reach them.  They were chew toys to her.  I learned to really dislike mice.

Keep after it hook, it'll work.

George
St Paul, TX

Offline Eric Garza

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Re: sinew backing question
« Reply #10 on: December 23, 2010, 10:06:11 am »
to further clarify I did used hide glue and sinew from 3 rivers however i did not clean the back of the bow before applying. I did size the bow and let it sit for 24 hrs and then started glueing, it was a little cold in the garage and i would say that the wood was about 45-50 degrees and there was some gelling of the glue rather quickly. I'd say all that added up to a bad glue job!!!! ....stupid beer!

What kind of sinew did you use from 3 Rivers?  I recently purchased their processed back sinew just to gauge the quality, and it was very poor.  The sinew was not scraped clean well to begin with, and its surface was heavily oxidized and it looked like it was starting to rot in places.  Even the best hide glue would not have worked well with that sinew.

Offline hook

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Re: sinew backing question
« Reply #11 on: December 23, 2010, 10:24:33 am »
eric,
it was processed back sinew and it looked white and healthy. The only thing was there was some fat on it towards the ends but i tried to pick that off.
this was my first experience with sinew!

Offline wodpow

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Re: sinew backing question
« Reply #12 on: December 23, 2010, 12:56:16 pm »
the glue wouldn't get a good grip when it was to thick  or to cool or the bow was cold and it started to set up before it got down into the wood and locked in. thats why I rough the back up with a hacksaw blade and put on a couple  hot thined out sizing coat of hide glue, hotter than you could put on with your fingers, but just that hot not much hotter. When you can pull off the sinew something wasn't right because it didn't get a super tough grip like it should. I thought about storing my sinew in cat litter  because it will draw any oils that may be on it I have seen fatty oils on my sinew when I dried it and I know it's still inside the tendon. 

Offline osage outlaw

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Re: sinew backing question
« Reply #13 on: December 23, 2010, 09:16:20 pm »
I had my first sinew job peel off.  My problem was that I used oil on the osage while heat bending it.  I didn't degrease good enough.  If you need more sinew, let me know, I have lots of it to trade.
I started out with nothin' and I still got most of it left