I finally have a nice dried and strait stave of black birch. I took it down to rough dimensions today. Its a pretty tough wood to work with a sg of .67. For some reason, I cant find my notes for finding the optimal poundage for a 2" wide black (sweet) birch selfbow. Its going to be 66 1/2" ntn. Can anyone give me a little advice? thanks.
You ought to be able to get a 45# to 50# overbuilt bow with sweet birch. It is stronger in compression and not so strong in tention, I believe. I've made a few but they were sluggish. Pat
That light for such a heavy wood? I was hoping for a different answer than that. :( huh
Try a piece and see what results you can get. It was a few years ago when I built one and since then I found other woods I like better. Maybe if backed it would work out better. We have a lot of sweet birch here. The twigs taste good if that helps any. Pat
The grain is really straight, so I'll keep it unbacked. I guess trapping might be an option here. I use this website for all my wood specs... http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr83.pdf
I see compression on there, but what do I use for the tension properties? Sweet birch is on page 27.
The winter hasnt been hard enough to start chewing on the twigs yet.
Even though the grain is straight adding a backing will add tention strength that I believe birch lacks. Both of us are lucky to have plenty of good bow woods where we live. I have played with most of them and have become partial to some and others I don't mess with. Birch is one I haven't messed with for a while. I do have a few staves in my work shop.
Sweet Birch is where oil of Wintergreen comes from. Primitives used the twigs for tooth brushes. It has a nice cooling taste to it. Pat
John, Trapping might be a good idea for birch but trap it backwards...wide back narrow belly. Pat