BBO?

[neuse]

I have an Osage stave that I want to back with Bamboo.

When do I put the bamboo on?
I am thinking first thing.
Then layout the bow, and tiller.

[Marc St Louis]

I roughly lay the bow out, that is close to finished dimensions, then back it

[Eric Krewson]

I do like Marc, I cut my bamboo out to a perfect pattern of the bow I want and thin it to the finished dimensions I want on my bow. I like my osage core to be slightly oversized, I glue the bamboo on the core lined up with a centerline on the core, after the glue sets up, I carefully trim the osage to match the bamboo back. I will leave the bamboo and core a little wider at the tips and thin them after the glue up to make sure the tips are aligned with each other.


I add 2 1/2 " of reflex on glue up, this will leave me with a straight limb or slightly reflexed bow after shoot in.

[neuse]

Very good, thank you.
I will start this soon.

[Muskyman]

After looking at that picture I’m thinking, I need a lot more clamps

[Lehtis]

Take a bicyckle inner tube, cut it lengthwise to two strips and wrap the stave with these. Tight rubber band gives proper compression, clamps may be easily overtightened and squeeze out glue; see the link.

http://www.primitivearcher.com/smf/index.php?action=dlattach;topic=69952.0;attach=159465;image

[neuse]

Are you using epoxy for the glue.

[Eric Krewson]

I agree with inner tube being as good as clamps and much cheaper. I started buying clamps when I first started making bows, people gave me some, If I found them on sale I bought more, I think I have about 50 now, I found the red ones at the el-cheapo tool sales are not worth bringing home.

Too much clamp pressure can cause glue starvation of the joint, after 26 years and at least 50 BBOs I don't have that problem, I do score the core and the bamboo with a toothing plane blade which cuts fine grooves and prevents starvation. I use Unibond glue for BBOs, I think the old Urac 185 was better but it is no longer made.

I also use clamping pads I made out of bamboo scraps that conform to the back of the bamboo and provide even clamping pressure. I flatten the back of the pad on a belt sander.

 

[Lehtis]

For neuse: I do use Smooth-On EA40 (epoxy).

[superdav95]

I used the same method as Eric with the contoured pieces of bamboo.  I also use ea40 with good results.  Only difference is I lined mine with leather. 

[superdav95]

The advantage over the inner tube using clamps is you don’t get as much miss alignment with the clamps.  The tube can twist the laminated glue up so just pay close attention on you set up to make certain no twist

[Eric Krewson]

I have used EA40 (good stuff) as well but always seemed to get more on me than the bow, hard stuff to get off.