BOOM!

[blackhawk]

Its simple...the grain is violated......think of it this way...

The grain is like woven fibers or strands in cordage,rope,or cable....so take a 8 strand rope that has a lift capacity of 100 pounds...and take your knife and make a bunch of partial severed cuts in it...now go ahead and try to pick up 100 pounds with it...it will prob make a few lifts,but you know its not safe and is going to fail sooner than later

[ionicmuffin]

i suppose that makes sense. Well either way. It blew and im glad it happened to me.

[Zion]

I don't know anything about board bows lol but what i've heard is that if you don't pick the perfect board it'll break, ya can't get very high draw weights from them, and the biggest, they cost money. Why not just go cut a sapling and make a bow from it? It's free and has WAY less limitations. Idk just my opinion.

[ionicmuffin]

well, i would, but this is for a trade thats supposed to be made of a board. My plan is to finish this trade and then to try to collect as many staves as possible. I also have a hard time finding good staves.

[lostarrow]

Hey muffin man, Is there anyway you could take some clearer pics? If those are the grain lines ,I don't know how you managed to get it to bend like this before the final attempt at heat treating.(Not saying it's impossible,just couldn't do it myself) It should have let go long ago. The fact that it broke in 5 places at once? Scary. Glad you weren't hurt. I know the guys are saying the heat didn't do it , and I'm not saying it wasn't the grain ,but If it was the grain only , you shouldn't have been able to do this , even if the wood was green.All I'm saying is ,now you know the effects that heat treating has on a bow.(looks like you toasted it pretty dark btw) Good luck with the next one!

[ionicmuffin]

in my opinion it wasnt grain entirly because it hasnt broken at ANY places in the grain! it was at solid rings where there wanst violation, thats whats weird

[autologus]

Only bow I have had blow up on me so far has been a white oak molly and that thing went off like a shotgun.

Grady

[lostarrow]

Not so weird muffin. Like I said on the other post , It'll likely blow if you cook it  trying to raise the weight on this one. Already high stressed design ,heated once before (? I think),Oak, board (so it likely started out with a lower mc) .That's a lot of strikes against you. To get the belly toasted that much ,the back was nearly as  hot when it's that thin. I've checked with a digital thermometer and with a real quick heat (just enough to start toasting with the gun about 1/8" away ) the belly starts to toast on oak around 200deg. and the back is at 160-180. I have also checked the weight  and found that it looses quite a lot % wise but regains  about 3/4 of what it lost and stops regaining after  2-3 hours.

[ionicmuffin]

well, i guess i will have to do more research on heat treating and all that good stuff. every time i see it its done from farther away. oh well.


OH! and before i forget! let my failure serve as an example for others of what not to do! This failure to make sure i knew what proper grain was didnt leave me scarred but it could have left me blind in one or both eyes, it could have really messed up my head or chest, lungs, or arms. Please to all that want to do board bows. Look for grain that looks like this. This would be the back of the bow.

[mikekeswick]

Have you got another photo of the bows back that isn't blurred!? Maybe using natural light.
From what I can make out the board was quarter sawn. Those black lines you've drawn don't seem to correspond to anything I see in the wood. It sure doesn't look flat sawn to me.
Yes grain is a poor word to describe how the fibers run 'grain' is ambiguous....
Think of wood fibers as being like rope, they are immensely strong when being pulled. Now imagine that you have lots and lots of them all laying parallel to each other.....but stuck together with weak glue.....they are still strong when untouched but as soon as you cut through a couple and then try to bend said piece of wood the 'ropes' will peel apart along the 'weak gluelines'. Why can you split a log with an axe on the end grain so easily? Weak glue! Try cutting straight into the grain.....

[lostarrow]

Just to muddy the waters a bit ,..................... the board you just showed could also have violated grain . Could even run off at 45degrees. It would just be harder to see. . If you have a knot in a quarter sawn or rift sawn board it will run across the face  instead of front to back. Now imagine if that knot was in the board next to yours  and didn't show at all in yours. You still have the grain that flows around the knot .

[bow101]

I had a good little White Oak board bow on the go as well. But I just did not tiller it enough, it was around 65# at 27".  Way to high, I pulled it beyond the point of no return and "SNAAAAPPPP" The grain was almost perfect, as good as any board I have ever seen.
Hasty is..Hasty does..!

[lostarrow]

Bow101 - Could you post a pic for  comparison and forensics?

[bow101]

Bow101 - Could you post a pic for  comparison and forensics?

Maybe at sometime, but the snap is about the same..

[lostarrow]

Did the break follow the grain lines ? Did you heat it at all? MC?