Author Topic: sinew lifted problem  (Read 2034 times)

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Offline sleek

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sinew lifted problem
« on: June 24, 2016, 06:54:08 am »
So at the recurve my sinew pulled itself off of the bow. What causes that and how do I repair it?
Tread softly and carry a bent stick.

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Offline osage outlaw

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Re: sinew lifted problem
« Reply #1 on: June 24, 2016, 06:57:36 am »
Did you use oil while heating the bow?  The only time I've had sinew come off like that was when I used oil.  I haven't used it since. 
I started out with nothin' and I still got most of it left

Offline PatM

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Re: sinew lifted problem
« Reply #2 on: June 24, 2016, 06:59:24 am »
Too rapid drying of the exterior with possible inadequate preparation of the wood surface.  Also, did you reverse string it to ease the strain on the sinew as it dries?
  You can fiddle around with fixes but sometimes it's better to just start over.

Offline sleek

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Re: sinew lifted problem
« Reply #3 on: June 24, 2016, 07:17:42 am »
No oil. Never used the stuff.  I keep the bow in my truck so possible it dried too fast?  I did not reverse brace it. Wood pres was a good sanding and soap water wash followed by scraping with a serated knife to texture the surface.
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline sleek

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Re: sinew lifted problem
« Reply #4 on: June 24, 2016, 07:21:25 am »
I think I will heat some water and brush it on to soften it, then apply more glue, then wrap it with strands of sinew. Sound like an intelligent way to go?
Tread softly and carry a bent stick.

Dont seek your happiness through the approval of others

Offline Mo_coon-catcher

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Re: sinew lifted problem
« Reply #5 on: June 24, 2016, 07:33:30 am »
It sounds like its worth trying. It can't hurt to give it a shot.
On the last one i sinew backed, I ran the sknew a little further than it needed to be and tied the ends down with of couple pieces of sinew. Jut for that problem of lifting at the ends.

Kyle

Offline PatM

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Re: sinew lifted problem
« Reply #6 on: June 24, 2016, 07:35:09 am »
Yep, drying too fast with no stress relief from reverse bracing.

Offline PatM

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Re: sinew lifted problem
« Reply #7 on: June 24, 2016, 07:39:32 am »
I think I will heat some water and brush it on to soften it, then apply more glue, then wrap it with strands of sinew. Sound like an intelligent way to go?

   Mix up your glue a bit thin and pour it in the gaps and let it gel and then inner tube and sun.  Wrap it tight because you want most of it to squeeze out.
  Then wrap those spots with cloth to slow the rate of drying and reverse brace it

Offline BowEd

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Re: sinew lifted problem
« Reply #8 on: June 24, 2016, 08:30:45 am »
+1 on what Pat M has said on at least a slight reverse stringing.The first day or two at least after sinewing the bow should be kept in a cooler place like at last below 70 degreees.No air movement.Closer to 65 degrees.That's for the collogen to gell up properly and deep enough to shrink down some.Then it can be put in a warmer with more air movement place.Kinda like drying heartwood of a denser wood really.Too fast in the beginning can show deep fizzure cracks into the surface also.
Your solution could very well work for ya if it's wrapped.Good luck.
BowEd
You got to stand for something or you'll fall for anything.
Ed

Offline Pat B

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Re: sinew lifted problem
« Reply #9 on: June 24, 2016, 09:24:21 am »
If your bow isn't a working recurve(but a static recurve) there is no need to add sinew to the non-working recurves plus it adds extra physical weight to the tips.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline bradsmith2010

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Re: sinew lifted problem
« Reply #10 on: June 24, 2016, 10:13:07 am »
 I have had some lift in the area you describe, as suggested ,, you may not need to put sinew there if it is static , also if it is working a bit,, a small sinew wrap in that area, or string wrap until it is cured would prevent that,, if it is  working,, maybe leave a small sinew wrap in that spot,,
ok about the comments about oil,, of course you can bend with oil and then sinew back,, you have to clean the back of osage oil anyway, if you use lye or strong dish washer soap and boiling water,, the back can be clean of any oil you used and suitable for sinew backing,, I have made alot of sinew bows, that were bent with oil,, and the sinew has stayed on as long as 20 years,,,
     just recently I had some sinew lift at the working recurve,,,it broke there as well when I first started to tiller,, so I did remove the sinew and start over,, i took a knife and carved off the sinew backing and then sanded,, I did not wash the back any more,, it has stayed on fine this time,, I think my problem was more glue related,,