Bow breaking

[Elison]

Hi guys!

I've made a bow backed bamboo but after a fews shots he developed this little crack in belly:

 

 

 

I'm wondering if is there any way to save him?

Thanks!

[robin]

Looks like a chrysal to me. Means the belly wood has taken too much compression. Plan off the belly and replace with another hard wood and re tiller

[Pat B]

Definitely a chrysal(compression fracture) and a bad one. The bow is toast unless you remove the belly lam and replace it. The belly looks like ipe. Is it? Can we see the bow braced and vat full(or at least 1/2 draw)? I'll bet there is a hinge right where the fret(chrysal) is.

[Elison]

Yeah...  that's I'm thinking.
The problem is I will lose the entire lamination.     :(  
Let me show you:

   

   

   

   

         

I used a reverse taper white wood between ipe and rosewood from the tips to mid-lam, and a taper white wood from the handle to mid-lam.

It looks nice for me, but I supose I need cut all this off and replace only for a ipe belly.  =(

[Bowjunkie]

Yeah, that's a compression fracture, but there's other stuff going on in that area too.

Behind the NEXT lam, the glue line/joint looks suspect, like the pieces weren't mated perfectly or clamped sufficiently. Also in the second lam it looks like it is broken or something because I see a crack on both edges... one of which, on the side with the heavy glue line, is in perfect line with where the compression fracture wraps around the side of the bow.... and in fact, this may be where the failure originated.

In other words, grinding off just the belly lam may not be enough. You may have to grind off the next as well.

[Elison]

I forgot the brace and tillering:

 

   

A few shots:

 

[Bowjunkie]

Ok, I see it now, it failed where your lam faded out mid limb. I'd grind that sucker out of there too.

[Zradix]

Originally posted by Bowjunkie:
Yeah, that's a compression fracture, but there's other stuff going on in that area too.

Behind the NEXT lam, the glue line/joint looks suspect, like the pieces weren't mated perfectly or clamped sufficiently. Also in the second lam it looks like it is broken or something because I see a crack on both edges... one of which, on the side with the heavy glue line, is in perfect line with where the compression fracture wraps around the side of the bow.... and in fact, this may be where the failure originated.

In other words, grinding off just the belly lam may not be enough. You may have to grind off the next as well.

I agree.

Looks like the core lam had a cross grain pin knot or something that caused it to break clean across. ( almost looks like you tried to put a splice in the working section of the core?)

Then your ipe tried to take up the slack...but couldn't.

Sorry bud..that sucks.   :(

[fujimo]

what a pity- looks like you put a lot of effort into that bow- sorry mate!!
ever tried an ipe stave- seeing as you are in its home range??
is there hunting down there?
cheers
wayne

[Elison]

Yeah...  there are two laminates affected by the chrysal.      

I think at first I'll try make what Dean Torges suggests here:
 http://www.bowyersedge.com/patch.html

I didn't know this technique, and I found looking for a solution. Hope it works.  
If don't, then I'll remove all te belly and put a new in the place. But only in ipe this time...  Here we can get easily.

Fujimo, no, here we can't have hunt.  It's forbidden...  the bow is only for target practice.  

Thanks guys, soom as possible I update here some news.  

Cheers

[Zradix]

good luck!

[macbow]

I've used Deans patch a couple of times.
Sorta successful.mhad to end up making the bow much lighter to hold up.
I know it can work .

[Pat B]

What glue did you use. Some glues release with heat. You might be able to remove the defective lam(s) and replace them.

[Elison]

I've been using Araldite Aw 106 to make my gluings...

Here the specs:
(http://adhesive.leaderseal.com/download/TDS-A106-953(US).pdf)