Author Topic: Need to bend ash stave  (Read 3994 times)

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Offline richpierce

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Need to bend ash stave
« on: August 13, 2007, 12:14:54 pm »
I have been working an ash stave a little and have it roughed out. It has natural deflex, quite a bit in fact.  A knot worked out perfectly- disappeared on the belly as I worked it.  I did not bandsaw the stave but instead tried to follow the grain, laying out a centerline and then making the rough-out the same width for the whole length (about 1 and 3/4" was what I could get from this stave).  Now I see a mild propellor twist and some snakiness.  Right now the limbs are about 7/8" thick and as I said, 1 and 3/4" wide.  It's 70" long.

1) Is now the time to straighten the propellor twist or should I work the limbs thinner first?

2) Regarding the snakiness, I guess I will have to have the string cross the handle, right, even if the limbs do not become perfectly straight?  Should I aim for stright or just getting the string to cross the handle?  Should I thin the limbs more first or just go ahead and heat and straighten it?

3) After I get the stave straighter, I need help deciding on limb shape.  I just want a bow that won't follow the string too much and will be durable.  45-50 pounds.  I will probably back it with linen fibers (got some flax).

« Last Edit: August 13, 2007, 12:16:30 pm by richpierce »

Offline Pappy

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Re: Need to bend ash stave
« Reply #1 on: August 13, 2007, 12:41:42 pm »
You should thin it till you can floor bend it just a little and will take the straightening better.I would try and get the propeller out and add a little backset at the same time,and if possible line the tip up
in the proses.You can always tweak that after you get the short string on it.I always oil down the limbs with cooking oil on white wood and try not to scorch it.I use a heat gun but any form of heat will do.Get it hot enough to touch but not hold and that will be about right.Try and figure what you want to do first and get everything set up so you can do it quickly when you get it hot.Then let it cool overnight is best or at least until you can feel no heat at all in the limb.Usually takes a couple of Hours.Hope this helps,good luck. :)
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Offline GregB

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Re: Need to bend ash stave
« Reply #2 on: August 13, 2007, 02:40:19 pm »
We usually have the bow roughed to the stage that only the limb thickness is excessive. The limb width along with its tapering to the tips have already been reduced to the lines usually. If you get the stave which I understand to presently be 1-3/4" wide full length to bending at floor tiller without first getting to the finished limb width, you might end up to lite in your finished bow.

When Pappy was talking about getting the stave to bend some prior to heating it, I'm pretty sure he was referring to the roughed in bow already being to the finished limb widths/tapers...only the limb thickness making the stave still stiff at floor tillering. Reducing that limb thickness is the last step we typically do prior to putting the bow on a form and heating. :)
Greg

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Offline richpierce

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Re: Need to bend ash stave
« Reply #3 on: August 13, 2007, 04:27:33 pm »
Thanks.  I will shape it to the tips then see if it will bend some then will heat it and straighten it.  I have no idea where to start for thickness to get it to bend but am guessing that 3/4" to 7/8" is too thick.

Offline Pappy

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Re: Need to bend ash stave
« Reply #4 on: August 13, 2007, 08:01:58 pm »
3/4 will probably be OK.It will wined up about 1/2 when finished maybe a little more/less depending on the wood and length of bow. :)
   Pappy
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