Author Topic: First time with sinew. Questions *UPDATE  (Read 4116 times)

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cool_98_555

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First time with sinew. Questions *UPDATE
« on: December 09, 2018, 11:06:16 am »
Hi guys,

I have a few questions regarding sinew.  I've never tried applying sinew before, but always wanted to try it.  I have an osage bow that is 64" long, stiff handle, and 1 1/4" at the fades with a straight taper to 3/8" tips.  If I am using back sinew, how many do I need for this bow?  I have been told 8 or 9, but I wanted to ask all of you.  Also, on this type of bow, is 2 or 3 layers even necessary?  Can I get away with 1 or would you recommend 2 or 3?  And lastly, is there a type of glue that works best or can I use something like titebond 3?

Sorry for the many questions here, but I just want to be sure.  Here are the questions in numbered format if you like that better.  Thanks for the help guys!

Bow:  64" ttt, 1 1/4" at fades with a straight taper to 3/8" tips.  Draw length is 29".
1) How many back sinews do I need for this bow?
2) Can I get away with 1 layer or do I need 2 or 3?
3) What type of glue is best?  Would titebond 3 work and be just as good as liquid hide glue?
« Last Edit: December 18, 2018, 12:10:03 pm by cool_98_555 »

Offline osage outlaw

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Re: First time with sinew. Questions
« Reply #1 on: December 09, 2018, 11:51:58 am »
For best results use hide glue.  Not the tight bond hide glue, get some unflavored knox gelatin.  It's cheap, easy to use, and works great.
I started out with nothin' and I still got most of it left

Offline bradsmith2010

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Re: First time with sinew. Questions
« Reply #2 on: December 09, 2018, 12:15:36 pm »
lots of varying opinions on the sinew bow, and  really it depends on the desired result,,
sinew varys in size, so weighing it will give you a better idea on how much to put on,,
I will just tell you what I would do,,
since the bow is a little long,, I would put at least 3 layers so it will hold some reflex,, without the reflex it will shoot about like an average self  bow and you probably wont gain anthing from the sinew,,its takes a bit of experience to learn how much sinew and reflex to put into a bow,, in theory a 64 inch sinew bow would draw,,32 inches,, with proper tiller your bow could shoot well,, but it is a bit overbuilt " in theory,,
I would use hide glue, i have used knok will success as well, there are guys here that will chime in,, with great suggestions and info,, (-P
« Last Edit: December 09, 2018, 12:29:51 pm by bradsmith2010 »

cool_98_555

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Re: First time with sinew. Questions
« Reply #3 on: December 09, 2018, 12:32:54 pm »
Thanks for the replies already.  I can cut it shorter to 60" or 62" and brace it backwards while I apply the sinew.  Would that do the sinew justice?  For weight, lets say 3oz.  Would that be enough for 2 layers?

Regarding the length being a little long....I should also mention that the bow is pulling 90# at 29" right now.  The high draw weight would stress the sinew enough even with 64", correct?  Thanks for the input guys.

Offline bradsmith2010

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Re: First time with sinew. Questions
« Reply #4 on: December 09, 2018, 12:45:12 pm »
yes I think at 90#,, the 64 inches is fine,, but it will still need reflex,, I made a 80# sinew bow with no reflex,, and it shot well,, just slow,,for its draw weight,, between 2 and 3 ounces should be fine,,

cool_98_555

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Re: First time with sinew. Questions
« Reply #5 on: December 09, 2018, 12:49:08 pm »
Brad if I were to brace it backwards how many inches of reflex would you recommend?  I don't want to lose any performance....if anything I want the sinew to add performance and retain the reflex put in.

Offline bradsmith2010

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Re: First time with sinew. Questions
« Reply #6 on: December 09, 2018, 01:00:12 pm »
have you shot it through a chrono at the present state,,
are you going to tiller it back to 90# or go with the increase in draw weight,,
I am spit balling ,, you will need to pull it to 5 or 6 inches of reflex,, and some of that will pull out,,,there is really no exact formula,,sometimes you do your best,, and just get what you get, no gaurantee,, but I think you are in the ball park,,,since the bow is already shot in,, an increase in performance may not happen,pound per pound,,,, except,, the added draw weight should give you more cast than you are getting now,,with same weight arrow,,
also,, since the bow is shot in and maybe has some string follow, I would be very gentle about pulling it into reflex,, I would probably gently heat the belly and very slowly induce the reflex,,or slowly pull it into reflex as the sinew is curing over a few days,,
« Last Edit: December 09, 2018, 01:09:08 pm by bradsmith2010 »

cool_98_555

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Re: First time with sinew. Questions
« Reply #7 on: December 09, 2018, 01:19:18 pm »
Yes I have shot it though the chrono already.  I will probably go with the increase in draw weight, not bring it back down to 90, unless I have to really fix the tiller.

Offline Stick Bender

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Re: First time with sinew. Questions
« Reply #8 on: December 09, 2018, 01:27:56 pm »
Be careful when reverse stringing I have had belly stress cracks before getting to aggressive reverse stringing ! The limbs need to be pretty thin for 6" but at 64" you probably be ok !
If you fear failure you will never Try !

Offline bradsmith2010

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Re: First time with sinew. Questions
« Reply #9 on: December 09, 2018, 01:38:45 pm »
and what is the bow shooting now, so I can get an idea of possible increase in cast

cool_98_555

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Re: First time with sinew. Questions
« Reply #10 on: December 09, 2018, 02:51:58 pm »
670gr arrow at 190fps, 880gr arrow at 168fps

Offline PatM

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Re: First time with sinew. Questions
« Reply #11 on: December 09, 2018, 02:55:55 pm »
Why are you sinewing it?

cool_98_555

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Re: First time with sinew. Questions
« Reply #12 on: December 09, 2018, 03:08:25 pm »
There is a very tiny crack perpendicular to the grain (1/16” wide) on the back of one limb and instead of putting a patch i want to sinew the entire bow.  I really like this bow.

Offline upstatenybowyer

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Re: First time with sinew. Questions
« Reply #13 on: December 09, 2018, 06:09:17 pm »
If your mostly trying to protect the back perhaps you should consider rawhide? How deep is the crack?

When I use sinew it's cause I've got a short stave of wood that's a good match for it. I know a lot of guys like the sinew/osage combo, but IMHO there are many woods that match better. Osage is just awesome on it's own.  )P(

If you decide to go with sinew, you won't need a lot to take the stress off the back.  :)

Wishing you the best!  :)
"Even as the archer loves the arrow that flies, so too he loves the bow that remains constant in his hands."

Nigerian Proverb

cool_98_555

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Re: First time with sinew. Questions
« Reply #14 on: December 09, 2018, 06:40:28 pm »
Crack is barely noticeable.  Extremely shallow but i want to ensure this is protected for the long haul