Author Topic: Help me analyze a break.  (Read 5499 times)

0 Members and 1 Guest are viewing this topic.

Offline J05H

  • Member
  • Posts: 478
Help me analyze a break.
« on: July 31, 2014, 04:40:55 pm »
This is the upper limb from an elm stave I broke about a month ago. I had the back smooth and nick free as far as I could tell. Its probably only my forth or fifth real break ( I've had failures due to splinters and cracks, just few breaks), so I could use a little help as to what kind of break it is. On the others the reason was clear. You can only learn from mistakes if you know why they happened, so I need a little help to keep from making this mistake again.



Thanks in advance for any and all feed back. Josh
If you never have time to do it right, you'll always have time to do it over.

Offline CustomArcher15

  • Member
  • Posts: 40
Re: Help me analyze a break.
« Reply #1 on: July 31, 2014, 04:47:08 pm »
Looks like it was weak in that spot and it just crumpled or the belly was weak.

Offline Crogacht

  • Member
  • Posts: 455
Re: Help me analyze a break.
« Reply #2 on: July 31, 2014, 05:20:32 pm »
Looks just like the break I had on my first elm. It broke at a weak spot from being pulled much further than it should have been at that stage.

Offline lukelawrence171

  • Member
  • Posts: 83
Re: Help me analyze a break.
« Reply #3 on: July 31, 2014, 05:24:40 pm »
from my experience elm seems to be sensitive to a bad tiller and break easy  it looks just like some of the breaks ive had

what part of the bow making process were you in?  it doesn't look like the back is clean enough  i like to sand it down to 300 grit before i put any pressure on the limbs

Offline paulsemp

  • Member
  • Posts: 1,918
Re: Help me analyze a break.
« Reply #4 on: July 31, 2014, 05:35:31 pm »
Almost looks like rot to me. How was it harvested and stored?

Offline Del the cat

  • Member
  • Posts: 8,300
    • Derek Hutchison Native Wood Self Bows
Re: Help me analyze a break.
« Reply #5 on: July 31, 2014, 05:36:57 pm »
Never seen one like that...
Del
Health warning, these posts may contain traces of nut.

Offline Pat B

  • Administrator
  • Member
  • Posts: 37,542
Re: Help me analyze a break.
« Reply #6 on: July 31, 2014, 05:46:16 pm »
Me neither, Del. My first thought was the stave wasn't handled properly of the stump and it became infected by fungi. Elm is pretty strong and you'd be hard pressed to break an elm stave like this if the wood was sound. IMO!  Will you post pics of the break from all sides?
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline PatM

  • Member
  • Posts: 6,737
Re: Help me analyze a break.
« Reply #7 on: July 31, 2014, 05:52:58 pm »
Looks like it's decayed to me. Was it left as a log for a while in warm conditions before working it down?

Offline Bearded bowyer

  • Member
  • Posts: 109
  • I'm younger than I look.........honest!
Re: Help me analyze a break.
« Reply #8 on: July 31, 2014, 05:57:14 pm »
any pictures of tiller....? massive hinge and rot?

Offline J05H

  • Member
  • Posts: 478
Re: Help me analyze a break.
« Reply #9 on: July 31, 2014, 06:29:16 pm »
I bought on Ebay from leenterpises and kept it in my house until I was ready to work it. I chased a ring and sanded to 120 grit. This is the last picture I took of the tiller because taking pictures was a pain. I was shooting for a holmie. Its at 18" in the pic, and was out to about 26" of a planned 28" when it broke.



It broke on the left limb in the pic at almost the center of the limb. I'll post pics of the break from more angles as soon as they upload.
If you never have time to do it right, you'll always have time to do it over.

Offline jasonoflivingston

  • Member
  • Posts: 25
Re: Help me analyze a break.
« Reply #10 on: July 31, 2014, 07:20:16 pm »
It almost looks like the wood may have been too dry. 

blackhawk

  • Guest
Re: Help me analyze a break.
« Reply #11 on: July 31, 2014, 07:41:07 pm »
One thing I do know and can see is that it is under designed and had a poor tiller judging by the pic you posted....how wide and long were the working portions only? Regardless of what it is tho your bend needs to be perfect with lever bows otherwise bang!!! And its even more so with Whitewood's....and regardless if it was rot or not try making your limbs wider and distribute the bend better before pulling it that far....if you were pulling it that far like it is in the pic then I am not surprised it broke,and that's even if it was good wood(no rot).

Offline mullet

  • Global Moderator
  • Member
  • Posts: 22,890
  • Eddie Parker
Re: Help me analyze a break.
« Reply #12 on: July 31, 2014, 08:08:35 pm »
It is not bending enough out of the fades and it's not Osage.
Lakeland, Florida
 If you have to pull the trigger, is it really archery?

Offline J05H

  • Member
  • Posts: 478
Re: Help me analyze a break.
« Reply #13 on: July 31, 2014, 08:36:00 pm »
I put a red arrow where it broke and blue lines where the levers were intended to start. It was 2" wide in the bending portion and 68" overall. I had evened it out a lot by the time it broke, but looking back I should have had it bending much better by 18".



So to recap, it was possibly degraded but definitely overstressed. I should have evened out the tiller far sooner in the process because elm can't take the abuse that osage or hickory can. Thank you all for setting me straight. Hopefully my second elm bow won't suffer the same fate.
If you never have time to do it right, you'll always have time to do it over.

Offline J05H

  • Member
  • Posts: 478
Re: Help me analyze a break.
« Reply #14 on: July 31, 2014, 08:39:55 pm »
Oh yeah, here are some more pics of the break.





« Last Edit: August 01, 2014, 01:05:55 am by J05H »
If you never have time to do it right, you'll always have time to do it over.