Primitive Archer
Main Discussion Area => Bows => Topic started by: sonny on December 27, 2009, 04:37:02 pm
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I've been working on this stave off an on for a while, just found a crack in the belly though there's no way of telling how deep it goes without removing too much wood, costing some draw weight.
I had planned on backing with sinew and could certainly add an additional course over the place where this crack appears.....
I guess my biggest concern is the crack opening up as the sinew dries.
suggestions and wisecracks are welcome....
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The crack looks like a check to me. A check is a compression fracture due to bending too much in one spot. Also looks like you heat treated the belly so it was probably too dry also when it bent there.
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if it was mine
i would make tomato stakes out of it nad find a nother stave to work on,that on looks to be doomed to me. jmho
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I'm sorry, I didn't mean check I meant to say a fret or chrysal but it looks like a compression fracture to me.
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Looks scary to me. dont know if I would keep going on that. Not to sure if sinew will help either.?. maybe if you backed it and wrapped it? Just an idea.
Tell
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Looks like you're going to need a patch to salvage that bow. ART
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yep, a patch like this one
(http://img.photobucket.com/albums/v181/ekrewson/100_0024.jpg)
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The only time I've seen cracks form dead across the limb like that is when I've tried to recurve with dry heat. I see scorching. Was this an area of attempted recurve or kink removal? I'm afraid it's dead as is. Patch it (per Erik) or burn it.
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That's definately a major fret = overstressed wood. You must have had a hinge there, or very uneven tiller.
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i would take it in stride and start another one, just dont hurt yourself.
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I would also set that one aside (learn from the mistake), and start another. It's going to fail eventually.
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Limited info. Where on the belly is it? It looks like, did you in fact dry heat? Under the pencil mark, how deep is the crack, fret, stress, or whatever you want to call it?
If it was me, if it is located anywhere on the working limb, I would scrape down to see how far it goes. May not be as bad as it seems. If you can get to the bottome of it, take both limbs down and tiller for a light bow.
Then............................4 layers of sinew. Sinew it up, let it dry, minor re-tiller and you've saved your bow.
But it's a gamble and it may go bust.
The best bows are the ones that you've had to solve problems with. The better bows are the ones that failed and you learned something.
Good luck.
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you could do what FVR suggested.
but it hink its awast of time,hide glue and sinew
but to each his won.
like said before
tomato stakes and a new stave
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.......with plenty of sinew on the back I'm of the opinion that it'll hold together. :-\
anyhow, the crack is near mid-limb, a little closer to the handle.
no telling how deep it goes. I reckon it could tiller out after sinew is applied.
what kind of glue should I use if I decide to patch it ??
I already have Resorcinol and Titebond 3.
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My patch was held in with Urac-185, it lasted 3 years of heavy shooting then the bow failed at the patch. I put a new limb on the bow and it is still shooting.
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Personally, that stave would be propping up tomatoes next summer if it were mine. That crack probably goes beyond the neutral plane and into the back. Jawge
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I would definitely not waste the time to sinew that bow, a patch maybe.
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I've been working on this stave off an on for a while, just found a crack in the belly though there's no way of telling how deep it goes without removing too much wood, costing some draw weight.
I had planned on backing with sinew and could certainly add an additional course over the place where this crack appears.....
I guess my biggest concern is the crack opening up as the sinew dries.
suggestions and wisecracks are welcome....
It's hard to say by the picture. I assume that mark is pencil to indicate where the crack is, looks like pencil anyway. Perhaps a close up on the side of the crack may tell how deep it goes, it will also show how much depth you have on the limb.
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You will learn nothing more by quiting now. Try the patch deal. Something good to know how to do if the occasion ever arises again. ART
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I was working a hickory stave a few months back. Worked the bow down and roughed it out, it was perfect with a big ol knot under the handle area. Limbs thinned down ready for tiller so I decided to design the handle.
Well, the nice knot below the handle that was perfect, was not. A little critter got in the middle and tunneled his way up up about 6 inches. I found this out while roughing the handle.
I scraped, scraped, and scraped knowing that the stave was shot but just wondering, if I could get it down to here, I could poss. with a little sinew make the bow.
Not the case, it's a tomato stake.
But I tried to fix it and learned a thing or two about bugs. Also, the gent that gave me the half log, after I told him about it, looked at the other half and has decided maybe not to put in all that work since he has a pretty ol knot on his stave.
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That crack can definitely be fixed, but it all depends on if it's worth the effort to you.
I have made bows of osage with some serious cracks and a good way to fix it would be to grind down the limbs much thinner and then laminate another layer of wood over the newly reduced limbs. You could use a layer of mulberry, hickory or even bamboo for the new belly. Since you planned on a possible sinew job, you then round the edges and have the sinew over lap the sides, thus covering the glue line between laminations and the sinew overlap helps to hold on the lamination.
Another solution is to grind the limbs thicker and reverse the bow, addign a sinew back. In other words make the belly into the back and the back into the belly. Simply sinew the belly as you would the back, and presto, problem solved. All Asian horn bows have the handle riser glued to the back of the bow rather than the belly. Once the sinew cover it the whole thing holds together incredibly well, provided you did a good job sinewing.
All this dramatically increases the work time, but you could still end up with a very viable weapon. It all depends on what you want.
If you are want a really easy way to laminate slats of bow wood, in a Primitive way, then use the asian horn bow method of cord wrapping and hide glue. They have a special wooden lever that a 1/4 inch rope is wrapped around the pieces to be joined. Usually one wrap per 1/2 inch of bow length is used from one end to the other. The lever wraps the rope so tight that it actaully cuts into softer woods and deforms them if you are not careful. It is much better than C-clamps. After it is wrapped simply heat up the parts slowly with steam from a tea pot and watch the glue joint. When the glue joint exudes the excess glue and the glue line is thin enough remove from heat and let it dry for a couple of days.
Here is a you tube vidio of the lamination and rope clamp method used on a korean bow...http://www.youtube.com/watch?v=E3cjk3-AHcI&feature=related
and... http://www.youtube.com/watch?v=93EoM77bCVc&feature=related
It takes a while to get to the part about cord wrapping the laminates together but the whole video is really interesting. It might prime some new ideas in you and expand your bow making skills.
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the learning curve that is wooden bows :) don't waist your time on it. sadly i would put it aside and start again. we have all had them, just move on and learn to read the wood and go slow.
it may have been drawn too far too early, there may have been a hinge there, it may have been a fault in the wood. it doesn't matter, just get back on the horse and ride again.
were you using some sort of tillering gauge. often the eye requires too much bending to notice where to work or not work next. a tillering gauge takes all the guess work out. i check my tiller with a tiller stick at brace height, not drawn, especially early on. shortening the sting as i improve until it is at a brace height of 6" or so. then you can draw it a short draw. check, adjust and continue to do so. i would suggest also that you do not hold it drawn while you go back and look at it. this is can be too much for the wood.
i hope you have better luck next time.