Primitive Archer
Main Discussion Area => Bows => Topic started by: Marc St Louis on May 20, 2016, 05:42:40 pm
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I cut a good size Yellow Birch about 20 years ago, made a few bows with the wood but was generally not that impressed with it so the rest sat in storage ever since. Last year I pulled out a quarter log and started wondering how it would do as backings. I squared the edges up and cut a quarter sawn strip for bending to see how it behaved. I was totally impressed with the wood. I could practically tie the strip into a knot except for where the strip was cut from the butt end. There it broke quite easily and I could see from the break that the tree had for some reason grown in a slight spiral for the first 20" so I shelved that idea. I sort of figured though that a plain sawn strip from this wood would be okay.
Now I'm not one to waste good wood and I had cut a belly strip from a primo HHB stave that I used to make a D bow a few months ago. The strip was only 1/2" thick at best but I knew I could make something from it if I backed it so couple weeks ago I decided to try the plain sawn Birch on it. Because the HHB was a bit thin I used a slightly thicker backing to make up the difference at the grip and tapered it aggressively for the limbs. You can see from the pictures that it worked quite well.
The bow is 61" N to N with 1 1/2" wide limbs tapering to 1/2" wide nocks. I didn't add any reflex in the glue-up until about 2/3 of the way down the limbs. The bow lost hardly any of the glued in reflex and finished up at just over 50# @ 28", I even pulled it to 29" to see what that would do to it. It's got some impressive string tension. Here's some pics of the finished bow
(https://i.imgur.com/pO49RAF.jpg)
(https://i.imgur.com/wPNJ5cc.jpg)
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That sure is bending beautifully. Nice!
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Nice.Cool.That's what's called putting strength where it's needed and less where it is'nt tapering like that.
You know I got a half form for reflex I use that puts the reflex on the outer third of the limbs where the work load is'nt so much on these limbs and am most times pretty pleased with the way the reflex stays and the inner third if of limb if tapered correctly does'nt take any set but stays flat.Usually but not always though the limbs are heat treated overall though too.
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Has anybody the latin name of yellow birch?
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Betula alleghaniensis according to wikipedia.
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Nice looking bow Marc. You sure didn't waste any material there. That full draw couldn't look better if you drew it in. Really nice bend.
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Thanks guys. I tried to keep the handle area as stiff as possible. No heat-treating done here
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Good looking bow Marc, everything is working nicely. Do you know what the bow weighs by any chance?
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Yep your glue line did that for ya.I've heard said it's the second best way to hold reflex on these bows besides it being naturally there.
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Cool combo and sweet bow Marc
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Thanks guys
Good looking bow Marc, everything is working nicely. Do you know what the bow weighs by any chance?
If you mean its physical weight then no, I don't have the means to weigh it accurately. If you mean it's draw weight then it's just over 50#, which I see that I wrote incorrectly in my first post
Anyway the purpose of this post was to pass on my findings about Yellow Birch as a backing. If you have access to some with straight grain then do not be afraid to use it as it's a great backing material