Primitive Archer
Main Discussion Area => Bows => Topic started by: sleek on March 16, 2013, 03:44:54 am
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So I did a hickory ax handle bow with a very short scarf joint, and a glued on handle for extra support, I even drilled holes and pinned it in 4 spots. Problem is, it is coming undone and at 25# of draw weight I can hear it creak as the pins that are in it slip a tiny bit. I dont want to do a wrap, I dont have time to redo it, what can be done?
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picutres? are you certain its coming undone? what glue did you use? where did you place the pins? how tight were the pins in the holes? what type of pins did you use?
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I can see it lifting and hear it creaking. I used tight bond 3, the pins are handmade hickory dowels, that required a hamer to get in. They were coaated with super glue just before driving in. The handle dried for 24 hrs before stressing it.
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put an overlay on both back and belly sidesthin it down some on the belly side, should be good to go, bub
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how short is short for the joint? it might truly be too short, similar to trying to join to boards without a joint at all, have you used scarf joints on bows before? im not even sure a wrap would help that much. thats a lot of force even with 25 lbs. have you ever held two pop sickle sticks in your hand and have them overlap? no matter how tight you hold them with your thumb and index finger it will just force your hand open. your problem lies in the fact that you have a lever acting against your joint. the longer the limbs the more force it will apply. in other words. If you have 25 lbs of force on the tips(or 12.5 per limb) and you say had 33 inches per limb each limb is then exerting close to 30 or more foot-lbs on the handle area. the longer the handle the less stress, the shorter the limbs the less stress. however, with a v or w splice you have not created a lever that will work hard against you. Hopefully there is a good solution
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Well, basically, it started coming completely undone. I got pissed, snapped it across my knee and went inside to ironically find my wife watching anger managment. The snap was clean at the handle splice, no damage to the bow. I am going to try to splice in a W splice using loctite gell superglue to speed up things. Then I will try to figure out how to laminate a pice on top as well...
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I would do a v or w splice on the handle when you redo it. I would still use tightbond 3 but make sure you're not using too much pressure on your clamps. Also if there isn't a backing on it you should probably put an overlay on the back as well to take some of the tension off the splice. How long did you make your glue on handle? I had alot of problems with this until I lengthened my handle sections.
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About a ten inch handle... gonna go with the W splice. Will go with the tight bond 3 again.
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I doubt you need ten inches for 25# I would go 8 if you want to be safe. The overlay on the back and the w splice will be the biggest help.
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This bow is actually gonna be a 40 lb bow, 25 is just where the joint started to fail. I got the W spliced in. Once its hardened up, I will do the top overlay, shape the handle and give it another go. If this failes, I'm gonna make a kids bow of it, and start another one. I have 2 more handles. Never had this much trouble with a splice before. Very irritating. I found that when I finally broke it, the joint was dry of glue. Think that was my problem...
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good luck with the splice. here is some advice. when you glue wood put a thin layer down, this is called sizing the wood this means the wood obsorbes this layer and then when that is nearly dry or tacy then you apply a second layer and put them together. don't tighten your clamps too tight as they will squeese out all the glue.
also have you considered takedown sleeves as then you can join them together and when it's not in use you can take it apart. but thats just a thought. i know mike has a video on youtube where he made a bow from pickaxe handles and he used sleeves he done a buildalong for it. heres a link
http://www.youtube.com/watch?v=Ul3Ft6KbtBs
hope this helps. SS
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Ok, I made sure to have sized the wood splice and over/underlays well, assured good squeeze out when clamped up without excessive pressure, did a double W splice ( inserted a piece with two male W ends to fit into the the two female W ends on the bow limbs to make up for length lost on the old splice I cut out. ) I think I am good now. Retillering now as I did loose an inche over all.
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Go to Walmart and get a ball of hemp cordage and a syrenge of 2ton epoxy and some acetone. Make a tight wrap on the handle(This is my regular handle wrap) then mix up some of the epoxy well and add enough acetone yo make the mixture watery. I use a rolled up paper towel to dab the mixture(Massey finish) on the cordage handle wrap and let it cure over night. This makes a very good, all weather handle wrap and is very strong. I came up with the idea on a boo backed yew bow that ended up being a tri-lam but still kept coming apart at the handle where the yew was joined. After the cordage handle wrap I never had the problem again.
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how short is short for the joint? it might truly be too short, similar to trying to join to boards without a joint at all, have you used scarf joints on bows before? im not even sure a wrap would help that much. thats a lot of force even with 25 lbs. have you ever held two pop sickle sticks in your hand and have them overlap? no matter how tight you hold them with your thumb and index finger it will just force your hand open. your problem lies in the fact that you have a lever acting against your joint. the longer the limbs the more force it will apply. in other words. If you have 25 lbs of force on the tips(or 12.5 per limb) and you say had 33 inches per limb each limb is then exerting close to 30 or more foot-lbs on the handle area. the longer the handle the less stress, the shorter the limbs the less stress. however, with a v or w splice you have not created a lever that will work hard against you. Hopefully there is a good solution
Yepp exactly, the limb tips are at a mechanical advantage they are working as a lever it's like when you try to open a paint can with your finger nails it's really hard but when you get something longer to pry open it opens much easier so basically the handle is under much much more then 25 pounds of force
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Well, here is an update on the hickory ax handle bow. I got it 60 inches ntn, 40 @ 28, and 2 inches of set. Tiller was spot on. Then for no reason I can tell, it blew up. I didnt get hurt, thankfully as once is enough for me a day. I dont get it, but I suspect that I may have taken too much off near the back of the handle when I did the back overlay over the W splice. Because that is right where it let go, right at the end of the splice. The break was a long one, looking for a spot to let out of the belly the break traveled 10 inches before leaving out the belly on the upper limb. The splice held fine though...
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well, like you said, its probably over stressed in that area and couldnt handle it. but your handle could! ;D
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Yup, and for that reason, I dont mind the break so much. The handle stood up to the stress. Ifthe handle had failed I would have flipped my lid, but the wood failed, and I am thinking I know why, so next time, I will have less bend out the fades on a splice job and more towards mid limb and tips.
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Glad to hear the handle held. It's too bad about the bow though, all part of the process. Good luck with your next one!
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Thanks bud, the glue is drying on it right now...