Primitive Archer
Main Discussion Area => Bows => Topic started by: TreyNC on March 06, 2008, 08:21:08 pm
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Hello all, I have been away for a while, life, you know. Any whay I am having trouble bending wood, I have never sucessfully bent any wood. Today I decided it was time to pick up a bow again, evidently it was not. I had a stave of white oak worked down to a single growth ring from last fall. I intended to bend the last 6" of each tip 3" in hopes of keeping around 1 1/2" - 2" of the bend. I boiled about the last eight inches of the limb for 45min. I then removed the stave and placed it on a board with a 3" block under it. Clamped it, then started closing the clamp on the tip. At about 2" I heard the crack. Now there is a crack (left to right across the belly) maybe 3/32" deep. At this point the stave is about 1/2" thick and 1"3/16 wide. The limb has retained 1" of bend. All of this happened from water to break in about 15sec. Is my wood to thin to bend?
Thanks for any help, I am feling pretty low about this right now. I have more wood to move onto just don't know if I have the energy right now. I am sure some one can clear this up for me and give me some renewed energy.
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No, you can't go too thin for bending. ;)
It might have taken too long for you to make the bend. If it takes more than a couple of seconds, I would put it back in for about another 10-15 min or so.
Sean
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I just broke the tip off a maple bow tonight trying to flip em >:( >:( >:(
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Thanks Sean, I will try to bend the other just to see what happens.
Dana, I feel ya. This is a horible feeling! Feels like my wife just told me shes leaving.lol
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Its just a bow it ain't THAT important ???
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You may be able to work under the crack and still have enough wood. Try taking a pot or coffee can full of water, put the part of the limb you want to bend over it and seal it off with aluminum foil. Get the water boiling and steam it for about 45 minutes - it will usually bend easily.
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Steaming white wood works better than boiling it , but you still have to work fast. If it starts to cool or you take to long, resteam it. I have keep it warm while I was squeezing the clamp with a heat gun.
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I had just put a lot into that stick a while back and had a vision of what coulb be and it all seemed soo simple. I think this will turn into a kids bow, I try to salvage all I can.
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How long is it?
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Trey...........1/2 " is a bit thick fer bending at the tips. I would think 3/8 " would be better. That shoiuld still leave ya plenty of wood ta play with........bob
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She is 62" long. I have mostly been building in the 66"-68" range bows with good results. I have tried two other 62" bows but have had trouble tillering them, I keep getting them whip ended. One of them shoots well, just does not look good at all, the other one broke. I am not putting enough bend near the handle.
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I know what you mean Tray,I have been there,it's tough but gets easier.I have
had some bad luck bending white wood,and Osage for that mater,so I always weight
the risk before I start,anytime you bend it backwards there is a chance it will lift
or break.I have found,you must be ready,everything set up before you start
and like Mullet said I keep a heat gun ready to keep it hot if it is taking to long.
Another thing,I know it is hard but try not to get to attached ,it is just a piece of wood
and this is a life long venture,you learn from every screw up.I tell GregB all the time
you got to have fire to. :) Now get another piece and get at it. :)
Pappy
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Like already mentioned, try and have everything prepared down to the clamps opened the right amount, etc. If you have a buddy that would help you, that really comes in handy as well when you have time limitations as is involved with steam bending. I did some straightening last night to a tip on an osage bow I had already recurved. Sometimes it takes several tweaks especially with a recurve before the limbs align properly. :)
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It's tricky. Steam it an hour next time, and then 2 to 3 seconds from steam to fully bent. Seriously, every second counts. It's not too bad once you've done a few successfully. 1/2" is plenty thin in my experience. 1 3/16" sounds pretty wide though. You might consider either a thinner section then add an underlay, or doing a kerfed bend if you continue to have trouble.
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Last winter i put some beautiful curves in a white oak bow with steam, around an hour for each limb,exatcly like Hillbilly described.I sinewed the back,began tillering then crack. An overlooked wormhole was the fatal flaw. Get your stave floor tillered use lots of steam dont rush,an hour per limb should get you there and oh yeah look out for worm holes!
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Yes, too thick. What little bending I do, is done after floor and long string tillering. Jawge
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Bending wood without knowing how the wood is responding (in a clamp, for example) has not worked very well for me either. After the last few months of learning to bend wood, my best results have been when I've bent wood over my knee or between two supports (like two small trees side by side). I need to "feel" when (or if) the wood is bending easily before I push the limits of the wood. I also found that bending in stages sometimes works better than bending all at once.
The secret the pro's use (to bend windsor chair backs, for example) is to use a steel strap (on the tension side) so that the wood only deforms in compression. Since you can't use a steel strap with most bow designs, just make sure that there is plenty of wood on the tension side while bending. In other words, if you're trying to recurve the tips on a bow with a rounded (or trapped) belly yer askin' fer trouble. ;D
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Thanks everyone. I have seen conflicting info on bending and realy don't know what I am doing. 1 3/16" is a little wide for my tasts but, I was trying to shorten the bow and spread the stress on the back in the hopes it wouldn't break. I also didn't know you could bend after some initial tillering. I am going to try the other end this evening to see what happens. Thanks again.
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OK, so I just bent the other end. I boiled it again for 1hr 5min. Time from H2O to finished was 6sec. and yes is broke. The fracture looks identical to the other end. The next one I will try to do some long string tillering first and then steam. I have a couple more roughed out to start thining and I think I can work below the fractured part (about 1/8"). That leaves me with 3/8" thick to see what kind of poundage I can get out of it.
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Trey, IMO, I think when you boil wood it is like using boiling water when you are cleaning a muzzleloader. I think it gets so hot internaly that it dries the wood too fast and doesn't hold the moist heat long enough.