Author Topic: BBO?  (Read 931 times)

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Offline neuse

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BBO?
« on: October 03, 2022, 08:18:20 pm »
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.

Offline Marc St Louis

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Re: BBO?
« Reply #1 on: October 04, 2022, 08:47:57 am »
I roughly lay the bow out, that is close to finished dimensions, then back it
Home of heat-treating, Corbeil, On.  Canada

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Offline Eric Krewson

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Re: BBO?
« Reply #2 on: October 04, 2022, 09:08:28 am »
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.


Offline neuse

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Re: BBO?
« Reply #3 on: October 04, 2022, 02:54:26 pm »
Very good, thank you.
I will start this soon.

Offline Muskyman

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Re: BBO?
« Reply #4 on: October 04, 2022, 05:37:58 pm »
After looking at that picture Iím thinking, I need a lot more clamps

Offline Lehtis

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Re: BBO?
« Reply #5 on: October 05, 2022, 12:53:58 am »
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
« Last Edit: October 05, 2022, 12:58:05 am by Lehtis »

Offline neuse

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Re: BBO?
« Reply #6 on: October 05, 2022, 07:42:14 am »
Are you using epoxy for the glue.

Offline Eric Krewson

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Re: BBO?
« Reply #7 on: October 05, 2022, 08:54:47 am »
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.

 
« Last Edit: October 05, 2022, 08:58:55 am by Eric Krewson »

Offline Lehtis

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Re: BBO?
« Reply #8 on: October 05, 2022, 09:40:25 am »
For neuse: I do use Smooth-On EA40 (epoxy).

Offline superdav95

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Re: BBO?
« Reply #9 on: October 05, 2022, 06:56:07 pm »
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. 
Sticks and stones and other poky stabby things.

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Offline superdav95

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Re: BBO?
« Reply #10 on: October 05, 2022, 07:11:57 pm »
The advantage over the inner tube using clamps is you donít 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
Sticks and stones and other poky stabby things.

superdav95@gmail.com

Offline Eric Krewson

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Re: BBO?
« Reply #11 on: October 06, 2022, 08:51:46 am »
I have used EA40 (good stuff) as well but always seemed to get more on me than the bow, hard stuff to get off.