Primitive Archer
Main Discussion Area => Bows => Topic started by: Utmostcone on January 28, 2013, 12:48:48 am
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Hello. can anybody identify what these are? i noticed them on the belly after heat treating my bow, they looked like cracks but i cant feel any wood lifting off, or any space. could it be crysalling or just growth rings? and if so is it safe to shoot? This is my 2nd bow so i hope i'll be able to shoot it well, or even hunt.
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It's hard to tell from the fuzzy pictures but, yeah, they look kinda like chrysals. Did they appear right after you heat treated it or have you bent it since you've heated it? Have they always been there?
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Those are Crysals and yes they are bad. They are crushed wood fibers or compression fractures. They will spell the death of a bow if changes aren't made to the tiller and the area patched
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how could i repair this?
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Repairing frets can be tricky and sometimes a waste of time depending on the bow. The bow Crysals are a result of the limb bending to much in that one spot, so the fix is to get the rest of the limb bending more to take the pressure off that spot and balance the force out. If you are already at weight then you will often end up under your desired weight for the bow. Repair to that area can be done a number of ways. Rawhide patch soak with superglue, wood plug or even a complete belly lam. But all that can still be futile if the tiller is not corrected. Some more info on poundage and actual picture of the bow strung would help to analyze
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I just strung it for the first time since heat treating and it will barely bend because it took about 2'' - 2 1/4'' of reflex during the treatment, so im going to tiller it some and il post the pictures once its bending.
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yeah those look pretty bad.
Every once and a while i get chrysals after heat-treating and heat-bending too, but not while the bow is actually bending. Usually they're by knots. Does heat treating and and chrysals have any kind of connection?
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Sometimes the belly wood will get brittle and fracture while it is under tension and being heated. If that is the case, it's not necessarily fatal.
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Hold on now. If you say this happened WHILE heat treating, then those aint frets. Especially if you forced the bow into reflex while doing the treating. They are tension cracks from over stressing the belly while heat treating and putting the bow into a reflex. If you dont feel any raised wood there, those are not chrysels. Just fill with super glue best as you can, scrape the limbs until you can brace it, tiller to your desired draw weight, and shoot. I think you will be ok.
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If indeed caused while heat treating then Sleek is right they are not compression fractures.
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Did you stress the bow too soon after heat treating it? Rehydration is necessary and especially in this dry time of the year.
How deep along the sides of the limb do the frets go? If not too deep you might be able to grind the belly down and add an appropriate belly lam.
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It would be great to see a full draw pic to determine if these are chrysals, and whether they're fatal. They sure look like frets to me, which are indicators of over stress.
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I am working on a Red Oak bow with flipped tips and when I steam bent the tips I got the same tension cracks on the belly of each limb, I just sanded mine smooth and wrapped the areas good with sinew soaked in hide glue. I will seal the whole thing with poly after it cures good.
Grady
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Did you induce reflex on a caul as you heated the stave? If so, this puts the belly under a tension load, and you get fractures. If you noticed them after bracing and bending the bow, then you've got compression chrysals (fretting). As has been mentioned, improper tiller and/or inconsistency in the integrity of the belly causes chrysaling. Correcting the cause (tiller) is paramount. Then, you can correct the symptom (chrysals). Here's a link to Dean Torges method, which I've used on a few times with great success on bows with knots I just didn't trust.
http://www.bowyersedge.com/patch.html
Autologus: Unfortunately, your fix won't correct the problem. Wrapping the limb with sinew as such is like wrapping your broken arm with yarn. It needs longitudinal reinforcement. I would suggest adding a belly lamination to the recurved portion of the limbs. This is easy to do and works like a charm. Looks nice, too. You can even taper the thickness of the tips slightly, as the laminated section will naturally be stronger because of the glue joint. Here's a work-in-progress picture of what I mean. This pic has multiple lams, but you can do it with one.
(http://i984.photobucket.com/albums/ae321/isaacscr/Trade%20Bow%20for%20Eric%20Thieman/HPIM5175.jpg)
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Well... i think its done :( i went to draw the bow to get the full draw picture and CRACK! lifted two big splinters off the back of the bow, directly opposite the belly damage. I doubt i can repair this :'( what do you think? maybe some glue and wrapping it would do the trick?
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I wouldn't. Especially if it's on the opposite side of the fret. It just means the bow was way over stressed at that spot, and it failed. Stand it in the corner, and go make another! Chalk it up to a learning experience.