Why did this bow break?#2

[mullet]

   It was interesting to see all the possible reasons the oak bow broke in the other post.So I thought we could try it again.This is the bow I made for my Grandson I posted back in July.It's made from an oak board from Home Depot.But it's silk backed.By the way ,the grandson wasn't strong enough to pull it very far.

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[1/2primitive]

It might help to see edge grain,          by the looks of it, I have no idea.
       Sean

[stiknstring]

Gonna be curious to see this one myself....looks just like the one that slapped my nephews dad upside the nose this summer.  Similar break, backed with two layers of drywall tape.  Could the silk backing in this case (or the drywall tape in my case) have something to do with it?

[Pat B]

That bow looks like it broke across the back possibly because of it was too dry or a flaw in the wood like fungi. If the bow bent too much in that area that could cause it also. Sometimes wood bows break just because!       Pat

[stiknstring]

Are you saying that sometimes wood just doesnt want to be a bow???

[DanaM]

I think a gouge across the limb could also be a possibility causing a hinge. But I'm gonna go with a bad spot in wood due to fungus, rot, insects whatever due to the fact its such a localized break.

[Pat B]

Stiknstring, Sometimes they break for no apparent reason...but not very often.   Pat

[mullet]

this is kinda like CSI,I'm curious at the guesses.When the responce slows down I'll tell everybody how it happened. I can guarantee there will be quite a few that knows.

[George Tsoukalas]

Too much grain run off. Look at the belly. The lines should be straight. tip to tip. jawge

[venisonburger]

I agree with Jawge, the break is right at the run off point.
Hey Jawge didn't you used to say something about the wood having a bow in it when you got a successful bow. I remember something like that from a few years ago when you were helping me out with board bows.
VB

[mullet]

   Yep,Jawge and VB are right.And I learned that from Jawges' site.That was the first board bow I made.I thought the run off would be okay since the yung'n was only 6 and couldn't pull the 20#'er back to 16 ".Well,on his 6 birthday,and this is the part I was talking about a few of you have seen.The other Grandpa,after a few beers,said, "this is a cool bow",as I said,"NOOOO",Pow! It broke at around 26".This bow was only about 46".If nothing else,If you are using a questionable board at least back it with something.It helped this bow take some nasty abuse.

[jcougar]

I'd say it was too dry.

[George Tsoukalas]

VB, I think I did say that. I tend to take incredible chances with marginal log staves. I'm really picky with boards though. LOL. mullet, I'm glad your grandchild was not drawing that bow when it broke.  Jawge

[Auggie]

Id have to say it was the grain, and boards from the depot, well its almost impossible to find a board of bow quality. Ive made several from boards,broke a few,had some good ones too.  just recently bought rudderbows new dvd how to make a bow,it deals with boards only, explains what kinda grain  to look for in a board,and how to from start to finish. Pretty good over all,they dont show how to make a tillering stick, but show how to use it well.I copied theirs cause I liked it better than the one I had.  Auggie.

[stiknstring]

I just followed Georges directions on his site to select a board and have only had problems with those that I decided to try AGAINST my better judgement.  Sometimes you just have to find out how far you can push some wood with a particular backing in the name of science.