How much sinew?

[Blaflair2]

How much sinew do I need to back a 52" bow? I'm talking deer leg sinew. I have 4 so far

[osage outlaw]

It will take more than that.  If you can't get any more shoot me a PM.  I have some I would trade.

[wood_bandit 99]

I have heard it takes 16 legs

[PEARL DRUMS]

About 10-12 decent length back strap sinews will give you a solid 3 courses.

[PatM]

A lot depends on your ability to shred the sinew and what your ratio of waste is per tendon.

[Blaflair2]

I don't have enough. I'm working on getting more. And I don't have squat to trade ATM. Thanks for the offer. 

I've never done it so ill probly say my ratio sux

[Pat B]

You'll want more on hand than you'll actually need just incase.

[osage outlaw]

Are you in the lower 48?  If so I'll send you some pieces. 

[Blaflair2]

Yeah I'm in NY. A lot of my buddies didn't get many deer this year

[osage outlaw]

Send me a PM with your address.  They might not be the longest pieces you've ever seen but they will definitely work.

[Marc St Louis]

I have done 4 courses with as little as 8 tendons with a bit left over.  It's all in how you apply it

[Danzn Bar]

Marc,
When you say courses are you describing layers of thickness??  Please help me with the terminology. and I guess you apply it very thin also.
DBar

[Marc St Louis]

When we say courses it means layers.  Most people apply sinew over the entire limb but I do not.  Many years ago I did some thinking on the subject matter and I deduced that it was not necessary to apply sinew that way.  What I started doing was to apply the sinew to maximize it's use plus keep the added mass as low as possible.  I figured that a limb does most of its tension work down the center where you have a crown and that the outer parts of a bows limbs do very little work.  I knew that sinew is more elastic than wood so it could stand to have a high crown.  What I therefore did was to apply no more than 1 course along the edge and the outer limbs.  Then moving were 2 courses progressing to 4 courses down the center of the limb.  This produced a higher crown, almost like a cable of sinew down the center of the limb.  All of the bows I sinew backed were short, highly reflexed static recurves and they all shot into the 180 fps with 10 GPP arrows using dacron strings.  I'm sure that with FF strings and a bit of tweaking of the design it would have been easy to shoot 190+.  Jeez, just talking about it makes me want to make one 

[Eric Garza]

For the last several years I've been doing it the same as Marc, lay down a ribbon of sinew down the center of the limb so that it creates a crown and focuses all of the tension on the sinew rather than the wood. Usually this ribbon of sinew is only 1/2 inch wide or so. If I'm worried that a splinter might raise as the wood bends, I'll put a layer of the thinnest rawhide I can get over the whole bow's back once the sinew's cured for a few months. I've found this approach offers me the best trade-off between the benefits of sinew (higher elasticity, holds down splinters) and the drawbacks (tedious work involved in shredding and applying it as a backing, higher weight-to-strength ratio).

[Danzn Bar]

Thanks Marc and Eric,
I have been researching this a lot and have come to the conclusion that more layers /courses or thicker sinew in the middle of the bow is best.  Thanks to Osage Outlaw I have enough sinew to build my first sinew back bow this winter.  I'm going to start this weekend.
Thanks again for the info.
DBar