Primitive Archer
Main Discussion Area => Bows => Topic started by: toomanyknots on March 16, 2011, 04:58:36 pm
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I kept hearing cracking sounds, thinking it was the string or something while pulling this bow, but after looking at the sinew I was afraid it might be my backing cracking. I didn't put that much glue on top of it, but I guess I might of put too much. I don't know. Is this bad?... ( :) ) It's only got one layer of sinew on it, so I'm scared it might break. This bow is sinewed from the dog treat tendons, and they might be treated in some way or baked or something, although I could not tell the difference between this sinew and any bought from a butcher.
(http://i52.tinypic.com/bi5kec.jpg)
It's got about 5 or 10 cracks running down one limb and a couple on another. Heres a video, much isn't that much better quality, but if you look close you can see all the cracks:
http://www.youtube.com/watch?v=B8FNUc8LiAU
The bows probably about 75 pounds or so at 28, but have only pulled it to around 24" or so at the most. One limb is twisty so tiller is no easy in the least to determine. This is only my 3rd sinew backed bow so I am hoping that this is just normal glue cracking. Note that I made the glue from the sinew pieces as well.
Some other pics-
(http://i56.tinypic.com/359bmtj.jpg)
(http://i51.tinypic.com/2hdvgnl.jpg)
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What glue did you use? Was it Knox by chance? I recently backed a bow with Knox and the bow cracked real bad everytime I pull it back, sounded like it was blowing up. And it showed the lateral cracks in it like yours is. I think I might have made the glue too thick.
CP
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"What glue did you use?"
I used sinew glue made from sinew scraps. If you make the glue too thick it can crack? I hope not, this did not happen I believe on my first two sinew backed bows. Or maybe it did, I don't remember. :( Should I be worried, the bows pretty heavy?
(http://i56.tinypic.com/j5jexf.jpg)
(http://i51.tinypic.com/1agox.jpg)
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I don't think you should be worried. I posted when mine started cracking and several guys said they had sinewed bows that still crack after years of shooting like an old rocking chair. I'm not sure if making it too thick or the type of glue is the problem or not, just a suspicion on my part. I had sinewed 2 other bows with Knox and they had never cracked. Then I sinew this one and it cracked every time, and LOUD. I let a compound kid pull it back one time and he nearly crapped himself, he was sure it had broke. Even though I warned him before hand that it was going to make that sound.
Here's what I recently did and it APPEARS to have worked. I ran warm water over the sinew areas where it was cracking several times, for a couple seconds at a time and rubbed some glue off with my hand, then warmed (and dried) the areas over a burner slightly to warm the glue back up and buffed the cracks out. The bow doesn't crack anymore but that was only a week ago. Ask me in 6 months how it's going. ::)
CP
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Brittle glue. ;D
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Well thats good, I was kinda scared from using these dog treats to sinew the bow, lol. It does got a real good bit of cracks now, but it sure seems to be holding up. Thanks guys! Next time I wanna try sturgeon bladder glue, I heard you can get it from any place that sells supplies for brewing your own beer/alcohol, which we have a store round here that specializes in that kinda stuff. It also specializes in foreign and exotic foods, so I figure I got a good chance of scoring me some...
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Good luck getting sturgeon bladders from a homebrew store. I've seen gelatin (dynamite fining) and chemicals but no sturgeon pipi tanks.
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The gelatin finings sold at homebrew stores are pretty expensive, and I really don't think the quality is going to leave good old Knox gelatin in the dust. I stopped using the gelatin finings on my home made wine years ago and if I want to pull out suspended solids I use Knox at 1/10th the price.
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Did not know that jw, I guess I will have to check out the asian food sections. I haven't found out much but have read stuff here and there I think of some nationality eating/selling sturgeon bladders, or some kind of fish bladder. I'm especially interested in the "stays liquid at room temperature" aspect of this stuff. Just so I might be able to stop sticking to everything...
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But sticky is gooooood!
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Just thought I would update this, right now I have about a thousand cracks per limb. The glue turned out really brittle. I don't know if it was simply the tendons I used, as they were probably baked since they were dog treats, or if it was fat or grease in the glue or something they added as a flavoring, or if I over heated it while making it? I don't know if I should try it again, as I have a bow I am wanting to sinew and was gonna use the same stuff for glue but now I am wondering if I won't just end up with a thousand cracks again... Does anyone have any tips or experience with brittle glue?
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Just thought I would update this, right now I have about a thousand cracks per limb. The glue turned out really brittle. I don't know if it was simply the tendons I used, ... Does anyone have any tips or experience with brittle glue?
You say you used tendon/sinew to make the glue. Could be your problem right there??
Does sinew make for as good a glue as hide does? You'd imagine they'd have different consistencies/properties...
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Somebody show how to make hide or sinew glue please,tutorial wanted ;D
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@ Young Bowyer
There are a lot of those tutorials around,latest i saw was at paleo
http://paleoplanet69529.yuku.com/topic/40529/Making-sinew-and-hide-glue
/Mikael
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thanks dbb gonna try this this fall after deer season >:D, need sinew n glue for the winter! ;D
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Making hide or sinew glue is not hard. Just put all your scraps in a pot, cover with water and simmer for a few hours, do not boil. Stir and remove the scum that comes up to the surface every once in awhile.
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Just like making acorn edible ;D
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"Does sinew make for as good a glue as hide does?"
Yes, sinew glue is bout as strong as hide glue, and has the same propertys. All the sinew glue I have made from sinew from the butcher has never cracked once on any bow I have made.
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How long did you soak your sinew in the glue before applying it?
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I actually soaked it over night. Was this too long?
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I say these are stress pionts when you tiller its just not right even though it looked good by eye. The sinew just showed where there at. I've had this happen with so early bows I sinewed. It will be fine but I always added a second layed. It was early in my bow building and did'nt know you could just leave it. So I just added another layer for protection. Which you can do if you like.
I sinew quite a few bows with all sorts of glues and thicketess. I would'nt think the glue would mater or it do it all over your bow. Not just in these few spots. I'd go with stress spots.
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This will sound silly. I know they use horse hooves for glue. Can they be used in the same manner? I can get all the hoof shavings and clippings I want.
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This will sound silly. I know they use horse hooves for glue. Can they be used in the same manner? I can get all the hoof shavings and clippings I want.
I thought it was used for glue too until i read a "how to" on hideglue that said it wont work because it is basicly just hair and lack the proteins needed.
/Mikael