Primitive Archer
Main Discussion Area => Bows => Topic started by: JWMALONE on April 21, 2018, 07:51:34 pm
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Hey Guys, Approximately how much sinew would I need to back an Osage bow 65 inches long. Say ten pieces of leg sinew?
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did you violate the back? Whats your reasoning for sinew backing and osage this long? The bows that I sinew used typically 2-3 oz, but they are 50-54" long. Im guessing it would be the same for a bow that long because it would more dispursed, and a thick backing isn't necessary, but sinewing a bow that long will just add weight. If you are trying to save a violated back, a lighter backing of a different material would probably be better, like a thin rawhide.
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Thin rings and I don't think I can chase one. I was thinking raw hide to start with, but thought sinew would be better. As long as it keeps the back intact it doesn't matter.
Thanks.
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If you want to use sinew, one layer would be enough, maybe 2oz, give are take. In your situation, where you are just trying to protect the back, rawhide may be an better, and easier option.
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What about a cedar bow?
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JW
why sinew?
Just my opinion, but I divide backings into two classes. One reason to back is to help an iffy back on an otherwise good stave. the backing serves to take some strain off the stave.
the other reason to back is to execute a design that calls for a special feature that cannot be done without a special materiel. for instance a design that calls for a bend that would be otherwise too sharp for the wood requires the extra sketchiness of sinew.
not to say that sinew cannot be used for the first, but more easily obtained mat' will work as well in a simple design with the usual materiel and at the usual lengths. Osage might be capable of even more than the usual . You might want to keep the sinew for a shorty or some special composite design. yes like a cedar bow or even a short cedar bow
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About 1000 grains or 2 0z like HD recommended I don't know your specific design sinew needs a lot of stress to compensate for the extra mass , you could add extra reflex to the bow above and beyond what you could do with out it ,you can lighten the sinew as you move up the limbs towards the tips there have been many bows like that built here if you can go threw the PA archives Marc ST Louis wrote a great article about how he did his 64 in. Maple static recurve a few years back , the problem with doing it with osage is you have a lot of mass to start with so a minimal mass design is needed to gain performance , but sinew bows tend to be more consistent & durable over time , also if your going to do osage clean your back well, I use boiling water and acid tone & toothing plane , you could also shorten the bow for your draw saving mass , about 10 rear leg Elk tendons should give you enough or more then you need ,depending on size , post as you go (-P
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Im not sure a layer of sinew and glue weighs much more than rawhide and glue, probably less. For me, it would be about ease of application in this case. I would choose rawhide and gain the same benefit one layer of sinew would give.
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Thanks Guys, I just want to reinforce the backing. This osage stave is pretty nice it just has thin rings. And ive never chased a ring. I knew sinew is used to add performance were raw hide doesn't. I haven't done much research on sinew. I do have a cedar stave, eastern red cedar or juniper, That I believe would benefit from the sinew, but like I said I need o do some more reading. Ill go with raw hide.
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Raw hide would be the better choice for just protection I use goat & TBB3 the mass is minimal and almost transparent , I use the kind designed for drum heads.