Author Topic: Unforeseen fret  (Read 3098 times)

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Offline Hrothgar

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Unforeseen fret
« on: February 27, 2009, 07:59:41 pm »
I've just discovered a problem similiar to Stixnstones'.  I had just gotten to the floor-tillering  part on a holmegaard takedown-white ash, 69" ttt. Dimensions are right where I wanted, straight billets, straight grain, no knots, no twists. I was just starting to smooth out the belly with 80 grit sandpaper when this faint reddish brown line started to appear. After more sanding I now have a 5" line (not a crack yet) right in the middle of the limb, running with the grain. Its about 2" from the bottom fade and runs straight up the limb. I went ahead and floor tillered this billet, it didn't get worse or make any sounds, but I'm not sure what to do at this point. I've put about 40+ hours into this project over the past three months. The back has already been backed with burlap--burlap wasn't my first choice, but it was available. Should I proceed with caution, or wrap the area with duct tap and just proceed? I've never used sinew before, but guess that is an option. Any advice is greatly appreciated.
Thanks, Eric
" To be, or not to be"...decisions, decisions, decisions.

Offline Jesse

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Re: Unforeseen fret
« Reply #1 on: February 27, 2009, 08:28:16 pm »
Hmm maybe just fill the crack with super glue and keep going?  Someone else might have a better answer
"If you can find a path with no obstacles, it probably doesn't lead anywhere."
    --Frank A. Clark

Offline DanaM

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Re: Unforeseen fret
« Reply #2 on: February 27, 2009, 08:31:07 pm »
If its running down the limb with the grain its not a compression failure ie fret, fill it with super glue and proceed wth caution.

Ain't makin bows fun :)
"Prosperity is a way of living and thinking, and not just money or things. Poverty is a way of living and thinking, and not just a lack of money or things."

Manistique, MI

Offline Pat B

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Re: Unforeseen fret
« Reply #3 on: February 27, 2009, 08:32:21 pm »
A crack running with the grain is not a fret. Frets run across the grain or diagonally. It is caused by over stressing the belly and it compresses the wood fibers until they break.
You have 40+ hours in this bow and you're only at floor tiller?  ???
   Floor tiller doesn't stress a stave enough to cause frets anyway.    Probably not a drying crack after this long unless you introduced moisture. So it must be a wind shake or other disturbance inside the stave that is just being uncovered.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline Hrothgar

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Re: Unforeseen fret
« Reply #4 on: February 27, 2009, 08:50:47 pm »
Thanks for the advice. I split several staves from this tree 4 years ago and this is the only "flaw" I've encountered.
Pat, actually there is more to this story. Last week I had a beautiful, fine, stained and finished holmgaard bow which had been pulled dozens of times to 26" on the tillering tree. The tiller was right on, the string lay perfectly down the middle of the bow from tip to tip, I had it braced and ready to go out side to shoot; then, a lesson: never pull, or jerk a bow when you are angry at one of your kids, especially past the intended draw length. Bottom limb broke mid-way, right above a knot I thought I had allowed for. Anyway, over the past 4 nights I have been working on a sister billet to replace the broken limb. Everything was looking real good until a couple hours ago.
Guess I'll take it real slow, maybe wrap some artifical sinew around the fret just in case (and do the same on the other limb for esthetic purposes.
Thanks, Eric
" To be, or not to be"...decisions, decisions, decisions.

Offline Pat B

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Re: Unforeseen fret
« Reply #5 on: February 27, 2009, 11:23:41 pm »
If my brain isn't into bow building, I don't build bows. Took me a long time to realize that but when I did it made 100% difference in my bows. I have screwed up some beautiful wood over the years because my mind was somewhere else and not with the bow. But, when real life steps in, bows take the back seat.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

nickf

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Re: Unforeseen fret
« Reply #6 on: February 28, 2009, 04:37:29 am »
2week ago I tillered a hazel bow out, 66" ntn, 60#@28", with a 6" huge crack running with the grains. still doing fine. Cracks running along the grain will only add character, imho