Yew break-help figuring out why.

[lebhuntfish]

Most of ya'll seen my post about Christmas in September. I received an amazing gift from hunterbob, a beautiful yew recurve selfbow.

I have shot them heck out of it in the few weeks since I received it. It shot really smooth and accurate. Only thing I done to it was put Beaver ball silencers on the string. I have put an easy 300 arrows through it. I spoke with Bob and he said he put at least 200 through it himself.

SSaturday at our gathering in springfield MO I was sharing it with my friends. All of which shot a few arrows out of the bow. Everyone that shot it had a shorter draw length than I do with the exception of one. He shot a couple of times with a really short draw.

IIn the process of drawing, one of my friends (a PA member I won't mention names) was drawing the bow. He only had it back to our maybe 20in when the top limb blew apart pretty violently. Everyone was ok. So we collected the pieces one of which flew over the privacy fence. We all looked it over and didn't really come to a conclusion of what happened. Plus it was starting to get dark on us.

I took some pictures and called Bob and we talked about it for a while. He said it was ok to post it on pa, that maybe we could learn something. So here is the pics of the carnage, can you guys help us figure out what happened?
Patrick

[Badger]

    Yew has a couple of issues that crop us some times. The rings will sometimes delaminate from each other, not always right away but after some shooting. Another thing is that yew is often sawn instead of split, it usually doesn't cause an issue but does leave an area not as strong as if it were split. I don't like yew below about 10% moisture if I can help it. The tension fibers get a lot weaker as they dry out.

[DC]

In the 3rd,4th and 5th picture there is a dark line/crack. Is that a check that was filled? I'm thinking that if that was an existing check it would indicate the grain direction.

[lebhuntfish]

Thanks fellas, I don't know a bunch about yew but so far I've learned a good bit already.

DC, you are correct that is a filled check in the back. It didn't go all the way through. It was linear and didn't run off the edge. But grain orientation seams to be shown there.
Patrick

[blackhawk]

Only thing i can see and critique judging by one full draw pic is that the bottom limb looks to be a hair to stiff...but that was a pretty dense tight ringed piece of yew...and yew can def take some small minor errors in tillering. But like badger said..sometimes yew can just be finicky stuff. Its one of the few very small downsides to it...and those little things like that about it make osage the king of bow woods...it has a higher consistency rate,and doesnt get dinged up easiky like yew does etc...

Im pretty sure the grain was faithfully followed as i saw this one in person before bob shipped it. ..im positive it wasnt because of that.

[DC]

I wasn't meaning the grain wasn't followed. I was wondering if the break was across the grain or not and I knew that checks follow the grain.

[Del the cat]

Shame, I can't see any real faults, but one point where it broke the wood looks dark and shiny like how it is inside a crack or shake. so maybe that's the weak point, also maybe the wood too dry?
Mind it's a good quality break e.g spread along the whole limb, which tends to indicate no one individual weak spot, just a catastrophic give out of the whole limb.
Del
PS.
I've just been working on a Molle' with some wood that had that sort of problem.
http://bowyersdiary.blogspot.co.uk/2015/09/yew-molle-iffy-wood.html
One place it started just splitting and bucking (glued and clamped it.) One lever was so bad, it was just falling apart under the rasp... I sawed off all the belly side of the lever and glued on clean wood.

[simson]

That sucks! This was a nice bow.

like the others mentioned, make sure you store your bows not too dry (I made this mistake and ruined once three super nice bows within 30 min).
Looking at the second pic: could it be there is a grain run out? Follow the filled crack and the break? Maybe heree is initial break beginning ...

[wizardgoat]

Ohhhh man that's a heart break!
Are the edges as sharp as they look in the photos?

[PEARL DRUMS]

I see grain running at 25-30 degrees. It broke on a grain line and that line is not parallel with the bow. Yew is almost impossible to read grain on. You never get a good look at the back and the sapwood just doesn't fully answer the question. 

[PatM]

I see what Pearlie sees. it looks like a slight propeller twist was straightlined. Picture gluing a bamboo backing slightly diagonally rather than linear. It's gonna pop on you.

[PEARL DRUMS]

I built an ELB several years ago that was cut out straight, but wasn't. It hasnt broke, but man did I play hell trying to get the string lined up. It never stayed where I put it until I used localized steam and TON of heat.

[sieddy]

That is a shame. It looked like a really great bow! 

[bradsmith2010]

sometimes an unseen flaw ,, not known to the bowyer will make a break,,,

[George Tsoukalas]

It does look like the lateral grain goes diagonally across that limb which is what PD was saying. Yes, it is a tough read. That'll do it on most woods with the possible exception of hickory. Good eye, PD. Jawge