Primitive Archer
Main Discussion Area => Bows => Topic started by: RedBear1313 on July 24, 2014, 11:52:28 pm
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got some small cracks on the belly of my first bow I'm working on here.
is this bow still doable or will it break?
these small cracks are on the belly.
(http://i185.photobucket.com/albums/x114/grymmtymm/Bows/1st%20Bow-Osage/20140723_222524_zps71b6325a.jpg) (http://s185.photobucket.com/user/grymmtymm/media/Bows/1st%20Bow-Osage/20140723_222524_zps71b6325a.jpg.html)
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Those cracks are what we call chrysals or frets. It is caused by the cells on the belly of the bow crushing and failing. There is no easy fix. Some guys have had luck with using a belly patch, but that's some advanced work right there.
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well I believe they formed while I was trying to straighten the stave out.
it had some twist and bend to it.
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Got a bit heavy handed with the reflexing....been there....time for a patch ;)
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How deep do they go?
How thick are your limbs?
If you haven't tillered the bow yet you might be able to remove them as you thin the limbs. I've had those on tips that I've flipped. I was able to remove them as I tillered the bow.
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what soy and osage outlaw said!
Mr Del (the cat) did a good buildalong patching on belly. You can find it here or at his blog.
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Good advice already given, sometimes if not to deep and on the compression side they don't give any trouble anyway. All you can really do now is carry on and see how it works out, I bet it will work out fine. :)
Pappy
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Next time, get the wood hotter before you apply pressure on it for heat correcting.
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Not really chrysals if they appeared due to heating the stave and bending it backwards.
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Yeah they do look like tension failures. I don't have high hopes for the bow's survival though.
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Yeah they do look like tension failures. I don't have high hopes for the bow's survival though.
they're on the belly side though.
yes, I know the wood needs to be hotter now, though at the time I did feel it was hot enough becuase it was pretty freaking hot to the touch.
they don't appear too deep but Im not bending just to test it. I scraped some of it out which got most of it but then after the wood darkened up some they look almost the same so hard to tell how deep.
Haven't tillered yet, though it's close to finished weight because I scraped some off due to those cracks.
that spot is about 7/16" thick.
plan is to just continue on but I considered backing and wrapping with sinew.
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You can get a tension fracture in the belly if you bend the stave into reflex(backwards).
I would fill the crack with super glue. Being on the compression side of the bow makes it less likely to fail.
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I've done it plenty of times taming a stave on the form. Happens even when you get it hot enough sometimes. Don't worry 2 much about it. They've never caused any problems for me...
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yeah I covered it with super glue right after it happened and have made sure to keep it nice and covered.
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Thought that looked like super glue on there. How heavy are you wanting this bow to be and how wide is that area of the limb? Also, how long is the stave? Best wishes and carry on man!
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Those look like chrysals to me, my friend unless you have not started tillering. Then I could be coaxed into believing they were done by bending.
I've been there too.
I can tell you how to handle them once we've ascertained how they were caused.
:) Jawge
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A tension failure cannot be a compression failure despite the similar look.
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True, Pat. That's why I'd like to know if he was tillering. Jawge
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The jagged edges are a clear indicator that it is a tension failure and not a chrysal.
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This crack is crack not chrysals. As DarkSoul said, the jagged edges are the clear indicator. This happens to me sometimes when there is a heavy bending with dry heat for some side correction. Most on Elm an BL, never seen on Osage.
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Oh it happens with Osage, even more readily according to the pieces I have tried heat on.
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Yep. Happens a bunch on Osage. Usually toward the tips. Can generally tiller it out and if I can't it is rarely a concern. Fill with ca glue and move on is what I would do. This is assuming it's not real deep.
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The jagged edges are a clear indicator that it is a tension failure and not a chrysal.
That was my thought too. Cracked during heat bending, it happens when it isn't hot enough or when you are really going for a big correction on a whoop-de-do or something. You'll notice this happened near the end of a growth ring where that ring was pretty thin. Also looks like there might've been a little hump right there, that focuses a lot of stress in a small area. If the crack is only in that ring, you could scrape it on down and get rid of it.
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I already know it's not going to be at the weight that I originally wanted.
So know I'm hoping for 40-45 lbs.
It's 63 in., and it's 1 3/8" wide at that point.
I was just reading yesterday through the 1st vol. Trad. Bowyers Bible in the section on glue and backing, and it stated that often when you back a bow with sinew the shrinking might cause cracks in the belly such as the ones I have.
So as of now I'm not going to worry too much about it.
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The cracks in the belly from sinew run with the grain, not across it. The sinew actually pulls the grain apart as it dries.
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Redbear,
Just got through with a sinew back osage that the belly cracked from drying, and it's shooting!....after fixing a crack that had nothing to do with the sinew issue.
Here is a pic of the crack that the sinew caused...................
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Sinew causing cracking of the belly is entirely different as the above pic shows.
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I was not, and have not yet tillered this bow.
I was using oil and a heat gun to correct some bend.
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I think you just didn't get it hot enough. Work the heat gun slowly. Sometimes I'll heat an area until it is to hot to touch, wrap in aluminum foil for a few minutes to allow the heat to sink in and heat again with the heat gun. I also heat as I am clamping and occasionally go back and heat more.
I also noticed on a stave I previously worked on with poor early/late ratio that it cracked easily with little heated bending. It also dented badly where I clamped it.
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I would not sinew as it pulls into reflex which will open that crack even further and possibly break it in half...unless you can get under the damaged area....I would play the safe route and do a torges patch ( sorry if I spelled his name wrong) but I'm a sissy like that lol ;D
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Sinew will not 'pull open' those cracks.
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Sorry if I'm passing bad info but in my thought process if you bend opposite a damaged area you tend to make it worse....I have had bad luck with that particular damage :-\