Broken bow: You make the call!

[Almostpighunter]

Hey guys!

Here's a little fun for you and education for me (and maybe some others on this site as well). I made this bow about 1yr.+ ago for a guy I shoot with. It is boo backed, purpleheart bow with a bubinga pistol grip riser. When I went to the range to shoot today, the bow was waiting for me in this condition with a message for me to call the recipient. I called but only got his message box.

So here's the game:

If you are so inclined, take a look at the break and tell me what you think might have been the caused it. Some info not in the pics:

1. The bamboo is still in pristine, like-new, condition (so much so that I'm probably gonna re-use it).
2. There are no indications of chrysals anywhere in the purple heart, including in the area where the break occurred.
3. There is a weird looking burn along with what looks like shredded wood in the handle (pictured).

I have the advantage of having the bow in front of me and I am able to touch/flex the limb so I have a bit of an edge here and I'm pretty sure I know what happened. However, I do not want to influence your answers so let's hear some diagnosis' from all you bow doctors out there.



[attachment deleted by admin]

[Thwackaddict]

high heat glue let go maybe

[Pat B]

It broke at a steep grain run off. Apparently the boo backing was too much for the purple heart belly and especially with the steep run offs.

[otis.drum]

agree with above. grain run off looks pretty bad.i don't think i've ever had a bow fail that far out the limb.... i look forward to everyone elses idea on this.

[half eye]

Allmost,
      Looks to the old man in pic's #2 & #3 like a counterflex break, because the belly wood is blown outward like a tension failure.....my guess would be that either the bow was dryfired and/or broken string.....or option 2 might be manually counterflexed (bent the wrong way manually)
      JMO since I aint got the thing to really look at.......just seems funny that the belly wood is split outward and not fractured like a compression problem.
rich

[Gordon]

That run-off should not have fractured in compression. My guess is that the bow was strung backwards.

[NTD]

I think the scorched handle plays into this somehow...It sure is odd looking.  Obviously the scorched handle didn't cause the break but I'm thinking what caused one cause the other...

[otis.drum]

did he run over it?

[Almostpighunter]

DING DING DING!!!! We have a winner...actually, "Winners!" Half-eye and Gordon both have identified what, upon close inspection, appears to be a counterflex break. What is tough to see from the photographs are the multiple smaller fibers that are exploding outward from the two major pieces as if the wood broke under tension failure as opposed to compression. Congrats to Half-eye and Gordon (and you boys win your choice of a cigar or a cupie doll) with honorable mention to Pat B as the break did indeed occur, for the most part, along the run off grain.

Frankly, I always felt a little patronizing when I told people who acquired a bow from me that one of the most important things to never do is bend the bow in the opposite direction (my layman's way of saying "counterflex"). It seems so obvious as something that would be detrimental to the health of the bow. And yet...

Anyway, let this be a good lesson to anyone who might be making a bow for another archer. Give them all the info you can on how the bow can, not only, be preserved, but about how the bow can be damaged as well. And rememeber, even if you do tell them everything...it doesn't mean they'll listen to you.

Oh, the burn...Actually NTD is right in that it wasn't directly involved in the break and it was more to confirm evidence of general misuse. Personally, I think there may be 2 potential explanations here:

1. The owner was thinking about either adding or carving an arrow rest (placement of the burn makes me think along these lines although I am at a loss as to the point of burning through the poly).

Or...

2. If the burn occurred around 4:20 p.m. it could have happened for another reason  and would also explain stringing the bow backwards     

[Del the cat]

Damn, I got here too late, but I was going to say it was bent the wrong way... I was honest..hey guys..trust me I'm a Cat.
(And that grain run off is pants too)
C'mon guys it's 9AM here, I got here quick as I could...
Del

[Justin Snyder]

Either one of Rich's ideas are legit. I have seen bows break like that when the string breaks and the tips just keep going. As for telling people not to flex it backward. You have to tell them everything or someone will do it.

Where did you get the purple heart? It doesn't look like true purple heart to me. Purple heart is usually darker with a lot finer grain than that.

[Pat B]

I was thinking that too Justin. It looks like ERC with a finish over it. 

[Almostpighunter]

Most of the boards I get come from a flooring supply store. Aside from the usual red oak at places like Home Depot and Lowe's, Vegas seems to be a relative wasteland as far as any bow building supplies are concerned (can't even find hickory easily). This is how I discovered purpleheart in the first place as it was an exotic looking board that was pretty cheap (about $5.99/board foot). The store itself is an absolute candy store for woodworkers with a great reputation; however, they DO seem to stock more product that is geared toward maximum grain exposure (it makes for more beautiful looking floor boards) so a thorough search and inspection of each board is required in order to find a grain pattern that is desired. In this case I knew I was backing the bow with the boo so I was a little more forgiving with the grain.

[Almostpighunter]

Oh and I do believe the wood is purpleheart as it maintains its color throughout the board as opposed to just on the surface from a finish. Initially when it is rasped the wood color dulls a bit and turns a little brown, but as it rests the color comes back and turns that cool purple hue. Some of the deep gouges in the  damage at the handle illustrate this and if I were a better photographer, or computer wiz, it would have been more visible.

@Pat: Sorry I may be having a brain cloud moment, but what is ERC?

[Pat B]

ERC is Eastern Red Cedar!