Author Topic: Do you need to have a sinew back?  (Read 24689 times)

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Offline TheDukesArchers

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Do you need to have a sinew back?
« on: September 15, 2014, 12:11:46 am »
When it comes to making horn bows, do you always need to have a sinew back? Would a bow that has a horn belly, but a wood core and back be considered a true horn bow?

I've been thinking actually of doing a Turkish style bow with a horn belly, hickory core and rawhide backing
DA

Offline Pat B

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Re: Do you need to have a sinew back?
« Reply #1 on: September 15, 2014, 12:28:32 am »
James has made them with boo backing and with boo back and tempered boo belly(no horn).
 Rawhide would only be a covering on a core backed horn belly bow.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

mikekeswick

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Re: Do you need to have a sinew back?
« Reply #2 on: September 15, 2014, 03:06:35 am »
Sinew = Essential!
Horn can bend about 8  times further than wood.....

Offline james parker

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Re: Do you need to have a sinew back?
« Reply #3 on: September 15, 2014, 10:03:38 am »
sinew is a must have component, rawhide will not do the trick ,a bow made that way will take a lot of set, shoot sluggish,
to be a true hornbow, composite,, has the sinew,, historically -- bamboo has been substituted for belly horn.
but ,, I only know from what I have read and my own personal experiences,,, if you do succeed at building a bow the way you are attempting, and it works for you,,,,,please let me know,, you can post it on the regular bows thread page,,,,    james,,

Offline PatM

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Re: Do you need to have a sinew back?
« Reply #4 on: September 15, 2014, 08:48:13 pm »
 Well Jaap Koppedrayer makes a bamboo back and horn belly bow with no sinew.  I'm pretty sure it is a local variation in Asia. There is really no reason to believe sinew is necessary solely because of the presence of horn.
 Horn is not going to increase the tensile forces on the back is it?
 The sinew is there so that the whole package can be strained to the utmost.
 Naturally the back should still be a high quality backing strip. I'm certainly not saying just leave a typical core to take the tension.

 Here is the page with the bow described. Scroll down to Asian Horn Bow. Try not to get too riled up. ;)
http://www.krackow.com/html/bows.html
 
« Last Edit: September 15, 2014, 08:52:27 pm by PatM »

Offline loefflerchuck

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Re: Do you need to have a sinew back?
« Reply #5 on: September 15, 2014, 09:00:48 pm »
Yes you can build a horn bow with no sinew but it will not shoot as well as a all wood bow. Horn is heavier than wood and without the sinew backing you cannot strain the bow past what you could do with just wood.

mikekeswick

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Re: Do you need to have a sinew back?
« Reply #6 on: September 16, 2014, 03:19:55 am »
What percentage does bamboo stretch before failure?
Personally I would see it as a waste of time making a composite with a bamboo back/horn belly. You just won't be able to strain the horn enough.

Offline PatM

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Re: Do you need to have a sinew back?
« Reply #7 on: September 16, 2014, 02:37:17 pm »
It doesn't matter if the bamboo stretches or not as long as the horn can take all the compression.

Offline james parker

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Re: Do you need to have a sinew back?
« Reply #8 on: September 16, 2014, 03:55:57 pm »
the original ? was
When it comes to making horn bows, do you always need to have a sinew back? Would a bow that has a horn belly, but a wood core and back be considered a true horn bow? I've been thinking actually of doing a Turkish style bow with a horn belly, hickory core and rawhide backing
DA

my reply:
sinew is a must have component, rawhide will not do the trick ,a bow made that way will take a lot of set, shoot sluggish,
to be a true hornbow, composite,, has the sinew,, historically -- bamboo has been substituted for belly horn.
but ,, I only know from what I have read and my own personal experiences,,, if you do succeed at building a bow the way you are attempting, and it works for you,,,,,please let me know,, you can post it on the regular bows thread page,,,,    James,,
I can assure you ,that bamboo cannot,and will not come anywhere close to the limits of sinew,, -(ever)
bamboo was not  part of the backing equation in the original post

Offline IndianGuy

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Re: Do you need to have a sinew back?
« Reply #9 on: September 16, 2014, 10:13:18 pm »
I'm no expert..BUT...I've made many sheep horn bows, elk antler bows, bison horn bows,water buffalo horn bows and James and chuck are correct.
The weight of the bow with horn and without sinew will be not very good to shoot, you need the combination of sinew and hide glue...Do Not use wood glue....and did I mention do not use wood glue?...I can see where the bamboo combo might work but I do not have any experience with that.
Lololol
Good luck.
E
« Last Edit: September 16, 2014, 11:19:38 pm by IndianGuy »

Offline james parker

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Re: Do you need to have a sinew back?
« Reply #10 on: September 16, 2014, 11:31:43 pm »
good points Indianguy
I have built all sorts of bamboo/horn/wood combos ,, they are a type of composite, and they will all shoot,, but have their limits,, as do ,,horn wood and sinew composites,, but the latter can be pushed much farther,,, and as far as wood glue for sinewing horn composite,,, such a waste of the natural resources when building hornbows,,  when using anything other than the natural fish/sinew glues, you will only get minimal to marginal results,, there can be little to no creep of the limbs going back to seasoned reflex... I consider it a short cut with short commings ---simply put ,a backing, nothing more,,...good for wood bows but not good for horn bows

Offline PatM

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Re: Do you need to have a sinew back?
« Reply #11 on: September 17, 2014, 10:11:18 pm »
So if a person made a tri-lam recurve with say a maple core, water buffalo horn belly and single growth ring backing of Hickory or similar, what would happen?

Offline Gaur

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Re: Do you need to have a sinew back?
« Reply #12 on: September 18, 2014, 01:59:33 am »
they would be wasting some good horn  ;D
"...He made me a polished arrow and hid me in His quiver." Is 49:2

Offline PatM

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Re: Do you need to have a sinew back?
« Reply #13 on: September 18, 2014, 12:22:17 pm »
Very skeptical. That would defy everything we know about how bows work.

Offline Gaur

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Re: Do you need to have a sinew back?
« Reply #14 on: September 18, 2014, 02:39:50 pm »
what besides sinew can handle the the opposing force in tension that horn can handle in compression?  Something like 2500 lb/inch if I remember right. You can make bows like you said with other things for backing but you aren't going to reach the potential of the horn.  Esp if we are talking about a profile with lots of bend in a short area like these Asiatic horn bows.
"...He made me a polished arrow and hid me in His quiver." Is 49:2