Primitive Archer

Main Discussion Area => Bows => Topic started by: DC on December 04, 2019, 04:47:13 pm

Title: Bamboo backing question
Post by: DC on December 04, 2019, 04:47:13 pm
I have a few pieces of 3/8" thick Yew. Nice clean(ish) stuff but at 3/8 thick it not quite thick enough for the inner foot or so of the limb if I make the limb 1 1/4" wide. I don't think I can make the limb much wider because of the crown on the 3-4" bamboo I have. I think I only need about 1/16" or so thicker for the inner third. I was thinking that if I make the bamboo backing 1/4" instead of the usual 1/8" that would give me the extra thickness I need. I could still taper it to 1/16" at the tip. The question is if there is any reason not too? Leaving it thicker would get me into the softer portion of the boo. Is there any chance that stuff won't glue well. Maybe something I haven't thought of?
Title: Re: Bamboo backing question
Post by: Hamish on December 04, 2019, 05:33:11 pm

If you have more width in the yew than 1 &1/4", that you want to use, I would treat the high crown of the bamboo, like a trapped back.

Add a thin layer of another wood for a core, to get a thicker limb.
Title: Re: Bamboo backing question
Post by: DC on December 04, 2019, 06:16:42 pm
As it turns out I can get 1 5/8" wide boo from the pieces I have. At that width they are .29" thick. I can't see going wider than 1 1/4 though. I haven't had any twisting at that width and apparently thicker/narrower is the way to go.
Title: Re: Bamboo backing question
Post by: bownarra on December 05, 2019, 01:37:30 am
No problem. I routinely put the taper in the boo backing. Takes a bit of practise to get perfect but no problem whatsoever.
Title: Re: Bamboo backing question
Post by: Del the cat on December 05, 2019, 03:11:40 am
I sometimes leave the boo a bit thicker at the grip if I'm a bit low on thickness. I can't see any problem.
Del
Title: Re: Bamboo backing question
Post by: leonwood on December 05, 2019, 06:24:49 am
I do exactly that sometimes, leave the boo a little thicker in the mid section to stiffen up the handle and fades. I taper the bamboo with hand tools (draw knife, rasp) and it has never failed or even given me problems
Title: Re: Bamboo backing question
Post by: HH~ on December 05, 2019, 06:47:07 am
I saw a guy cut tapers on a table saw in Hawaii. Turned boo on edge and ran it down a carpenter line he would put on it.

 Cut lots of yellow bamboo in the Jungle of Hawaii. Not native but it grew well. I would cut and use standing dead boo. It will overpower some bow woods if you leave it to thick where bow bends the most for sure. Good seasoned Boo is a must because it will check after its on bow in many cases if its not plenty seasoned. It will do so very slowly over time or if it gets wet again and drys.

HH~
Title: Re: Bamboo backing question
Post by: DC on December 05, 2019, 11:29:23 am
Thanks guys. I'm using the boo in two pieces to get the nodes the same on both limbs so I will be putting a "power lam" under the boo to tie the limbs together. That will give me even more thickness near the handle. Now as long as I've guesstimated right :D