Author Topic: Bending a limb sideways  (Read 2600 times)

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Offline DC

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Bending a limb sideways
« on: June 01, 2017, 11:46:34 am »
I want to bend the tip of one limb sideways a bit. I can use steam but it takes a while to cool/ dry. Is it OK to use dry heat? Normally when I use dry heat I confine the heat to the belly but if I'm bending the limb sideways I'll want to heat a different area. Would some heat on the back be OK as long as I don't brown it? It would be about 6" from the tip. It's Yew.

Offline PEARL DRUMS

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Re: Bending a limb sideways
« Reply #1 on: June 01, 2017, 11:51:42 am »
You think too much, Don :) . Just heat that 4" section of belly ONLY up and move it over. Wait an hour or so and continue on.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline DC

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Re: Bending a limb sideways
« Reply #2 on: June 01, 2017, 12:25:40 pm »
Tryin' to think of a snappy comeback, but I got nuthin' :D Thanks PD

Offline Dances with squirrels

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Re: Bending a limb sideways
« Reply #3 on: June 01, 2017, 12:52:54 pm »
When making such heat corrections on seasoned, dry wood, I heat it evenly with a heat gun held in my hand and constantly moving... about 3" from the surface, all the way around until it's just about too hot to hold in my hand, then go for it.
Straight wood may make a better bow, but crooked wood makes a better bowyer

Offline Del the cat

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Re: Bending a limb sideways
« Reply #4 on: June 01, 2017, 02:06:21 pm »
With a wide limb, I'd rather try to bend at the grip where it's narrower.
Del
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Offline DC

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Re: Bending a limb sideways
« Reply #5 on: June 01, 2017, 02:43:29 pm »
I'd already bent it at the handle to get the bulk of it in line. I just needed to get that kink out to get the whole thing right. I actually planned ahead this time. Saved me a couple of bends :D :D

Offline Marc St Louis

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Re: Bending a limb sideways
« Reply #6 on: June 01, 2017, 05:42:15 pm »
Actually what I do is heat the edge, applying the heat more towards the belly side than the back.  Make sure if you do it this way to heat the outside of the bend so that when you bend it you are compressing the heated side otherwise you could get a stress crack (tension failure).
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Offline Dances with squirrels

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Re: Bending a limb sideways
« Reply #7 on: June 01, 2017, 06:47:40 pm »
Imo, adequate, even heat makes wood more elastic all around and throughout, and so helps negate the effects of both tension and compression when we force it to change shape... and it works better if all of it is permitted to change in any area we bend. If one side shortens, allowing the opposite side to lengthen, by way of sufficient heat,/elasticity means less stress for both sides. Heat/elasticity allows it. Cold/rigidity doesn't. If we don't heat a portion of it, or heat it less, it will try harder to resist our efforts. Don't just heat one side, don't heat one side more than the other, and be patient, keep the gun back and moving, and you won't get checks or frets. Wood is a poor conductor, so give it time to transfer the heat in toward the center as much as possible. Just my 2 cents.
Straight wood may make a better bow, but crooked wood makes a better bowyer

Offline Pat B

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Re: Bending a limb sideways
« Reply #8 on: June 01, 2017, 07:13:20 pm »
I'd wait until first brace to see how the string tracks. You may be able to remove wood from one side to line the string up.
If I had to straighten with heat I'd add oil to the belly and sides and heat it until I could bend it and use wedges to move it over.
Make the most of all that comes and the least of all that goes!    Pat Brennan  Brevard, NC

Offline PatM

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Re: Bending a limb sideways
« Reply #9 on: June 01, 2017, 08:45:46 pm »
Imo, adequate, even heat makes wood more elastic all around and throughout, and so helps negate the effects of both tension and compression when we force it to change shape... and it works better if all of it is permitted to change in any area we bend. If one side shortens, allowing the opposite side to lengthen, by way of sufficient heat,/elasticity means less stress for both sides. Heat/elasticity allows it. Cold/rigidity doesn't. If we don't heat a portion of it, or heat it less, it will try harder to resist our efforts. Don't just heat one side, don't heat one side more than the other, and be patient, keep the gun back and moving, and you won't get checks or frets. Wood is a poor conductor, so give it time to transfer the heat in toward the center as much as possible. Just my 2 cents.

 The thing with heating and bending is that changes of shape apparently take place by wood compressing since wood basically doesn't stretch. So if one side shortens, the other doesn't have to stretch.

Offline wizardgoat

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Re: Bending a limb sideways
« Reply #10 on: June 01, 2017, 10:16:41 pm »
Don, with yew I've always had horrible luck making lateral corrections on working limb areas. It always pulls out during tillering. I always try to get a big bend in the handle for string alignment, and maybe in the outer limbs.