Best way to take out prop twist?

[bigcountry]

I have a few osage bows unfinished.  Two of them have bad prop twist.  Wood if very dry.

I heard steam is a no-no for dry osage, and can make a crack.  

I have never used a torch.  Can I?  What should I coat it with to keep from scorching?

Should I try to straighten out by bending in the handle, or just twisting the tips over?

I have a heat gun but doesn't get hot enough.  I have to hold onto the bow like 1min 1" away just to get hot enough to make it so its too hot to touch.

[PV]

Steam works well with osage if you get the wood hot enough.If it bends easily it is ready to bend.If it's not it will crack.Sometimes it will crack anyway.#?%## Reducing the section you want to bend to a single growth ring will help or using a metal strap on the belly will also reduce your chances of a crack. The fastest and best results I've had is with a heat gun. I think I paid around $20 at one of the home improvement stores. Has a high and low heat setting.Takes me 5 - 15 min depending on  thickness and width to get the wood to hot to touch.If the wood is ready it will bend fairly easily. Used to use grease but now just dry.Keep the heat(torch or gun) moving back and forth over the part of the bow you want to bend and this will reduce scorching.For prop twist I start correcting it where it starts from the handle out.

[talkingcabbage]

Bigcountry,

Check around at some other posts here.  I know I've seen other discussions, some with pictures.  If I'm not mistaken, osage likes the dry heat better than steam, like you said.  Some guys will take mineral oil and soak the wood in the area they're heating.  This helps the heat get into the wood more evenly.  Then (depending on how bad the twist is) clamp the bow in a vise and get a cresent wrench on the limb with the twist.  Hang weights off the wrench to twist the limb back to straight, then let it cool there.

Do you have any pictures of the twist?  

Joe

[Pat B]

If the twist isn't too bad you can either tiller it out or just don't worry about it. George Tsoukalas has a section on his website that goes into limb twist. He has an example of a sound bow that has excessive prop twist.
   Dry wood, dry heat. Wet wood, wet heat!
   I prefer a heat gun and olive oil for straightening osage. If you have a form to clamp the bow to you can correct the twist with a little bit of heat and a few small wooden wedges and add a bit of reflex at the same time.
   If your bow is tillered you can do this with a heat gun(no oil) and actually scorch the belly wood(to brown, not black) to increase the compression strength as well as eliminating the twist. Pat

[bigcountry]

Thanks Pat.  One on osage, I just tillered it out best I could by taking off material.  

I think I am going to invest in a wagner 1600watt heatgun.  One I got now I checked is a master heat 600watt.

[Pat B]

You can get a decent B&D heat gun, with 2 settings, for about $20. The one I have goes to 1200w. I bought it years ago at a garage sale for $5 and have used it for many straightening and bending projects.

[bigcountry]

Hey Pat, on yew, do you use heat gun also?  Or steam?  

I am still working on that yew bow I discussed with you a few months ago. I just put it aside for a while and it was full out hunting season.

[shamus]

A propeller twist is nothing to worry about.  As long as the twist is because of the how the wood grew and not from improper tillering then you're fine.

Untwisting a propeller twist is more likely to cause damage than do any good.

Work *with* the wood not against it.

[bigcountry]

I hear ya shamus, and there is a lot that agrees with that idea, but a lot does not too.  A bunch of bowyers like to take out the twist.

[Pat B]

Most wood bow bowyers don't worry too much about the prop twist in bows. As Shamus said, Work with the wood, not against it.
   I use a heat gun(with oil) on the yew I just posted on the Rawhide thread. Yew reacts very will to heat. The only time I use wet heat with dry wood is with white woods like hickory and I seal the area to be steamed with shellac to prevent moisture from getting back into the already dry wood. The shellac can be removed later if necessary but any finish will go right over it.

[Tommy Leach]

Big Country, I built an Osage bow a few years ago that has a twist of 65 degrees tip to tip. The string lays over the canter of the handle and it shoots good. Your buddies will be amazed when you pull out the crooked stick and see how it shoots. Let the wood determine the bow. The only time I use heat (dry) is to move the string over the handle or put R/D into the limb. Good Luck!

[OsageBowyer]

Howdy big country,Primitive Archer mag vol 2 issue 3 has an artical by D.M.Kissinger on this topic you might find interesting titled "see whats really there" as for heating my bows I have found there is usually enough wood shavings left over from shapeing to heat and straighten most of my unacceptable deviations just pile em up and light and it's a good way to keep your work space clean.

[bigcountry]

I now don't shape my handle and leave a lot of material, just for prop twist.  I still hate it and would love to take out most of it at the handle.

[Roy Steele]

For me heat is a no no.I kike to leave my bows natual.This makes the bow more durble.I leave my tips stiff but if not to bad I just remove wood off the other side of the twist.If that dos'nt work for you do what I just said then back it.Thicker sinew no the side you've taknin the wood off of.Or any heavey type materal will work.

                             ROY