First time for everything

[Muskyman]

I’ve only made about 8-10 bows. I was pretty happy having never had one break, but that’s over.
I was doing some inlay practice on another bow. Once done I was looking for something else to do and picked up a bow I had started a while back. I was checking the bend and draw weight it exploded with a very loud bang. I bent it back together and started looking and found the culprit. I think. The second picture shows the belly right where it broke at. I’m kinda glad it finally happened because now I have a better idea of what to expect

[Selfbowman]

Looks like the back failed just out of fade to me.

[bjrogg]

Looks like the back failed just out of fade to me.

That’s what I’m seeing too. It looks like it failed in tension not compression.

It probably was bending a little too much right out of the fade.

Bjrogg

[Muskyman]

Was a bit of a knot pretty much right on the edge on the back too. Right where it broke. I never liked the look of it from the start, that’s why I put off into my pile of maybe someday bows. Probably should have looked it over before I started bending it. No matter. I’ve got plenty other stuff I want to work on. It was kinda mushy feeling too.

[Hamish]

Musky, I'm guessing you didn't  leave a bit of extra wood around the knot?

[Muskyman]

Turns out it wasn’t a knot Hamish, just a dark spot. There is a knot on the back in the area of the failure but I’m not really sure what caused it. I took a few pictures just so you guys can see it a little better.

[Muskyman]

Guess I put the same picture up twice

[Kidder]

That looks like a straight tension failure to me. The wood also looks very dry and brittle. How recently was it heat treated? Also your edges appear a little sharp to me although it’s kind of tough to tell in pictures. None of those might be the culprit though - sometimes they just blow. Learn what you can and on to the next.

[Muskyman]

Kidder, it was heat treated a few months ago and has been in my shed outside since. I think it was overcooked myself and that was another reason I had put it aside.. might have been too close to the heat. Seems like I remember scraping a lot of the charred wood off it. I don’t know if I have another from that bunch, don’t think I do.

[GlisGlis]

The wood also looks very dry and brittle.

+1

[Pappy]

Happens to the best of us, the wood dose look very dry to me also but that knot area probable done you in.
 Pappy

[superdav95]

It looks like a tension failure to me too. a few questions... is that hickory?   how long did you do the cook?  was it with a heat gun or coal bed?  It does look very dry but hickory should be able to handle this.  Ive had similar looking failures that were a result of mineral streaks that ran parallel with grain.  Ive also had tension failures around pin knots and buried knots that extended to the belly.  What i found on these instances was that the relatively stiffer harder wood around some of these buried knots can create a hinge or extra tension on both sides the knot.  possibly too much concentrated bend in that area too early on may have caused the tension failure.  It is more unusual to have hickory fail in tension and more common to see compression failures.  just some thoughts from some of my similar looking failures. 

[Muskyman]

It’s hickory Dave. I don’t remember much about the cook time. It was a long time ago, at least 3 months. Probably just over cooked it. On to the next one for me, or playing around with stuff I still have going on. Got some other hickory laying around but it’s got some pretty bad propeller twist in it. Can I steam that out or is it firewood?

[Muskyman]

Got curious about the moisture content in the stave so I took it out to my shed and checked it with my moisture meter and here’s what I found. Just to check the meter I tested a 2 x4 at about 13 plus percent. First picture is from the handle and second pic is the break.

[superdav95]

It’s hickory Dave. I don’t remember much about the cook time. It was a long time ago, at least 3 months. Probably just over cooked it. On to the next one for me, or playing around with stuff I still have going on. Got some other hickory laying around but it’s got some pretty bad propeller twist in it. Can I steam that out or is it firewood?

You have some options.  You could steam out the twist and then allow it to rehydrate a bit before heat treat.  I’ve messed around with heat treatment lots here and I find it hard to believe you over cooked it.  The back dos t look scorched either.  On your prop twisted stave just get it to floor tiller stage or brace and then remove your twist with steam.  If the twist isn’t too bad then you may be able to just use a reflex form and clamp it down good removing the twist while introducing little reflex at same time.  Once baked holding to this form it should remain and not return to its prop twist.