Cause of break?

[ShorterJ]

Both bows I’ve made blew up. First one was an accidental dry fire and blew a few shots after, but the second one I don’t know.  I was going to brace the bow for the second time after floor tillering and it broke across the back. 2 inches wide at the break and it is hickory. I didn’t think this was a weak spot especially with it being so wide and not bending exceptionally more than other spots. The break looks strange to me; what do you guys think?

[Yooper Bowyer]

I think a square break like that generally indicates weak wood on the back, and that looks like it is mostly early wood or somewhat infected.

What I want to know is why it broke there.  Was there a kink in the grain, or maybe it was overstrained somehow.  Hard to tell exactly why there without seeing it.

More photos would really help, especially looking straight at the back.

[ShorterJ]

Here are pictures from the back. There was curvature in the grain, but I followed the grain. The limb hadn’t started to taper to the tips yet so there shouldn’t have been any runout. I was wondering about the stave having some sort of issue since it cracked on the back rather than split along the grain.  Just under the crack on the back the wood splits along the grain like normal almost as if the wood on the back is bad and the wood underneath is good. There are odd brown streaks in the wood just under the back also. I got these staves from someone else, so I’m not sure how much they were cared for during the seasoning process.

[PatM]

Looks like the wood is degraded.  Hard to say how it was treated after cutting without knowing for sure.

[ShorterJ]

I was worried about something like that.  The bow before this was made from the same set of staves, but I went underneath the wood on the back because I was worried about the weird streaks in it. It held up fine until I went and dry fired it.

[PatM]

It does look like it was left wet for too long in a  questionable environment.

[Pat B]

For hickory to break across the back like that it would have to be rot. How has it been stored since it was cut?

[ShorterJ]

All I’m sure of is that it was in a shed for about 5 years and the ends were sealed with paint with the bark left on.  I’m not sure how dry of an environment it was.

[bownarra]

The wood is compromised for certain. In what way exactly you can't tell from here.
To break a hickory bow like that is not normal!

[Dances with squirrels]

See that black crap inside the break just under the surface of the back? That's rot. That's the effects of not seasoning wood properly from the minute the tree was cut down. This is why I like to cut and care for my own bow wood whenever possible, especially white woods like hickory, elm, hophornbeam, etc which are more sensitive to how they're cared for. Degraded wood such as that cannot survive the bending. If they're not quite as bad as that, (they don't have to SHOW rot to have rot) and they somehow do survive the bend, they can take immense amounts of set.

Root cause? Improper care. Maybe not by you, you may have acquired it after the damage was already done.

The overwhelming majority of wood isn't cared for the way conscientious bowyers care for theirs. It generally doesn't have to be.

[ShorterJ]

Thank you all for the input and information. I feel better knowing that it was the stave and not me this time.

[scp]

See that black crap inside the break just under the surface of the back? That's rot. ....

I agree. It happened to me a couple of time with staves that I split from a hickory log delivered to me just several days after being cut down. Rot can probably happen in just several days. Or it might be tiny injuries in the bark even before cutting.

I would try to use such staves as quarter-sawn boards. That way I can avoid any surface defects of the tree. Still I only make light draw-weight bows out of them, say less than 35 pounds.

[JW_Halverson]

I am gonna echo the guys saying that the wood had spent too much time wet somehow and was degraded.

On the other hand, I spent a little time looking at the grain of the back of your bow and the outline of the limbs. Brother, I have to give you high marks for following the grain. Keep that up and you'll never lose a bow to that particular mistake!

[scp]

Any black lines like that in hickory, or any light color hardwood should be avoided.