self bow limb twist

[josef2424]

Ok guys, I've got another question...Every self bow that I have made has limb twist in it. I have heard a couple of solutions such as: using a heat gun or using hot water of some sort, but I have no idea how to properly go about using either process. Can anyone tell me which method is better and if there is a how-to post on this?

[Dano]

First question, did these bows start out with limb twist? If they didn't you might be taking off wood unequally from the sides of the limbs. If they did start out with twist, what I do is put the bow in a vice attach a pipe wrench to the twisted tip, heat and bend the limb to right direction to remove the twist, then tie the wrench in place for a while. Hot water is for glass bows.

[kodiakkid]

I have always been told to use dry heat (heatgun) on dry wood and wet heat (steam) on wet wood. That is what I have always done. My wood bending is very limited but the above has worked well for me. Heat the belly of the bow until it is to hot to touch and twist in the opposite direction of the twist. Be careful not to scorch the wood. Twist a little further than needed as it will return a little. Like Dano said find a way to tie it off while it cools. You may have to make a couple adjustments.

[Springbuck]

The basic set up is as Dano described.  If the bow is dried and tillered, or even partly tillered, you just have to find a way to torque the limb the direction you want while clamping it down closer to the handle.

  I use a hardwood board with a slot in it that fits over the limb instead of a pipe wrench, but same principle.  I like to use a heat gun, because you can torque a bit, heat it and feel the wood relax,  twist it further while heating another area and gently move along the limb doing that.

[ichiban]

why do people only use wet heat on wet wood and dry on dry?? you would think using steam on a dry wood would aid in penitration and stop excessive moisture loss? in my mind it would be dry heat on wet wood and wet heat on dry wood

[John Scifres]

Dry heat checks wet wood.  You can steam dry wood especially if it is sealed.  After steaming raw wood, it is a good idea to let it equilibrate in cool conditions before tillering or it may check on you.

[josef2424]

Thanks a lot guys for explaining this to me. I feel a little bit smarter now. Looks like im gonna go invest in a heat gun. And when you say not to scorch the bow, does that mean not to burn the wood so that it turns black? And also I have heard that wood shouldn't be too dry or else it will be too brittle and crack. So does that mean I should let the bow sit in the humid, Georgia air for a while before tillering it?

[ChristopherO]

It depends on the wood how dry is too dry.  Hickory responds best very dry, 6%-8%, while other woods needs 8%-10% to not be too dry.  The Traditional Bowers Bibles have a chapter or two about moisture content in the different woods.  May want to check them out.

[George Tsoukalas]

Limb twist is not bad, LOL. You've learned how to deal with it apparently. Jawge

[va]

The questions to answer are like Dano says:
1.  was the twist original or
2.  due to uneven wood removal,
3.  OR are the limbs getting twisted during brace?

I ruined several of my early bows because I could not do the push-pull brace method correctly.  Now I build my bows so a stringer can be used - AHA! no more twists.

[Pat B]

...but, was the stave twisted or did it take the twist will  tillering(uneven wood removal)?

[Dano]

That's what I was askin.  

[josef2424]

Oh. Sorry. I forgot to say that I haven't even started tillering it yet. The stave is twisted because I followed the grain very precisely, and the grain twisted around the log a bit. I also sometimes use calipers to make sure that the wood removal is even-so that isn't the problem.

[Dano]

This statement led me to believe you might be doing something wrong. "Every self bow that I have made has limb twist in it" Carry on, sorry.

[Pat B]

Get it to at least floor tiller stage before you deal with the twist...if at all. A bit of twist doesn't matter with self bows. We call it character! d;^)

[George Tsoukalas]

How much twist? Is it enough to make you want to "Twist and Shout"? And work it on out! Sorry. LOL. I agree though selfbows have to be straight, have no knots, no twists and look like glass bows. They have to look like they came of an assembly line rather than an individually crafted work art. They have to be homogenous. Something like this. Nice sweats ha?  Jawge
 http://georgeandjoni.home.comcast.net/~georgeandjoni/aerobow.html

[George Tsoukalas]

Sorry about the sarcasm. Tough day yesterday. Very tough. Jawge