Primitive Archer
Main Discussion Area => Bows => Topic started by: Ifrit617 on October 12, 2013, 08:33:37 pm
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Hey all,
In Gordon's hazel build along he did a few years back he used a piece of thick rawhide to patch a chrysal. The most recent bow I've been working on has developed a few small chrysals about 17" from one tip and I was thinking of using a similar patch. How effective do you all think this method really is? Probably going to get some dog bone rawhide from the pet store and see how it goes.
Jon
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I think Gordon realized that a rawhide patch over a chrysal is entirely cosmetic. It has to be.
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Just curious why that is?
Jon
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It works. Usually when a bow chrysals these days I don't shoot it much. To relieve the area, retiller above and below the chysals, since they are caused when the limb bends too much in that area. Then do the patch. retiller the other limb to match. Jawge
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Rawhide has no compression strength. The chrysal is still there. You're relieving the stress by re-tillering, not putting a thick piece of "tape" over it.
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Rawhide has no compression strength. The chrysal is still there. You're relieving the stress by re-tillering, not putting a thick piece of "tape" over it.
+1
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I don't use that technique anymore. If chrysals develop I now generally discard the bow.
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If a chrysal is in the outer 1/3 of the limb then cut it there and make a short kids bow.
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I would normally discard the bow, I have noticed on some locust bows that I would have normaly trashed that the chrysals have remained shallow and don't seem to affect the bow but once I see them I just have no more confidence in the bow and it will really never be used to any extent.
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I would normally discard the bow, I have noticed on some locust bows that I would have normaly trashed that the chrysals have remained shallow and don't seem to affect the bow but once I see them I just have no more confidence in the bow and it will really never be used to any extent.
It takes a certain amount of faith to hold a wood bow at full draw. Once I see chrysals, my faith in a bow evaporates.
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I would normally discard the bow, I have noticed on some locust bows that I would have normaly trashed that the chrysals have remained shallow and don't seem to affect the bow but once I see them I just have no more confidence in the bow and it will really never be used to any extent.
It takes a certain amount of faith to hold a wood bow at full draw. Once I see chrysals, my faith in a bow evaporates.
Me too. There is a lot 'going on' at full draw ;)
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What Gordon/Badger/Mike /PatM said. +1 :)
Pappy
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A chrysal is a mistake. Period. It's either an error in tillering, design, or wood selection. It's a flaw caused by over stress that will eventually lead to failure. I've only had a couple bows chrysal (cherry and walnut) and they were both my fault. Both bows were abandoned to the scrap pile, and lesson learned.
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The only thing I disagree with is that a chrysalled bow is more likely to break. Wood is stronger in tension so a collapsed belly puts less stress on the back. A hinged chrysal perhaps but not a chrysal with no apparent disruption to the drawn profile.
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Well, the long time bow makers have to remember that they have many bows in reserve.
Newcomers do not.
A chrysalled bow can be fixed and can last for awhile. It will not last "forever". It will eventually fold on itself like closing a book. . Don't ask me how I know that. LOL.
There are 2 causes for chrysalls.
First, if the design is stressed (too short, too narrow, too much weight) the bow could develop them. In this case they will be spread out over one or both limnbs and likely all along the limbs.
Second, the chyrsalls are localized and form in certain areas because the limb bends too much there. The fault is bad tillering. To fix, leave the chrysalled are a alone and retiller above and below to fix the tiller. Retiller the other limb to match. For insurance add a rawhide patch to buttress the area.
Jawge
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Still not sure how you think something with little bend resistance is buttressing anything. The thickest rawhide patch available can still be bent and creased with bare hands.
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The only thing I disagree with is that a chrysalled bow is more likely to break. Wood is stronger in tension so a collapsed belly puts less stress on the back. A hinged chrysal perhaps but not a chrysal with no apparent disruption to the drawn profile.
Pat, proably most of the bow failures actually happen at the belly before the back breaks. Once a bow has chrsaled it is weak there and can hinge and cause an instant failure at any time.
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Once a bow has chrsaled it is weak there and can hinge and cause an instant failure at any time.
+1
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That's the reason for the patch. It's temporary. The bow will fold up there. Jawge
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I have heard people taking needles and putting holes above and below it then put sinew on the back for a patch