Help with hickory twist

[kiltedcelt]

Well, I'm working on an un-backed hickory board bow. The bow is 70" NTN 2" wide at fades tapering starting halfway down to 1/2" nocks, also a 4" non-working handle. Floor tillering went okay and so far regular long and short string tillering is looking okay but then I noticed the twist. It's literally twisting one way on one limb and twisting the opposite way on the other limb. Can this be corrected by shaving the side of the limb opposite the twist or on the side of the twist, or do I need to get out the heat gun and have a go. If I have to use a heat gun, how do I go about that?

Pics:

You can see the limb closest to the camera twisting to the left while the opposite limb twists the opposite way.


Here you can see a dark patch of grain that runs the whole length of the bow - seems to be tougher than the other lighter grain (heartwood?) - could this be a factor?


Tiller - still needs work but I halted so I could get advice on the twist before I go any farther.

[Dave 55]

I believe if you carefuuly take some wood of the strong side you will have what you want.Actually some propeller twist isnt a big deal.

[Jmilbrandt]

I wouldn't mess with it it's not a big deal.

[Timo]

Don't look to bad to me either.I've made them alot worse. The string track looks good.I wouldn't worry about it.

[George Tsoukalas]

kiltedcelt, both limbs show a lot of bending mid limb. Get some more bending on both limbs close to the handle and pay heavy attention to the near handle wood on the left limb. I assume you didn't pick out a prop twisted board so uneven wood removal probably caused the twist. The stave twists towards the weak side so remove wood from the other side. Those limbs look awfully thick to be pulling that far so be gentle. LOL. Jawge

[DustinDees]

i have used hickory boards for all but my first bow sofar. the darker is heartwood, lighter sapwood. i love splitting the bow as close as i can in half with heart/sap great contrast, i have not noticed any more twist than your bow than is showing on any of mine and they shoot great. as you tiller you can take a tiny bit more from the side it is bending towards and it should help.

Dustin D

[kiltedcelt]

Well, I don't have to worry about fixing the twist any more. I managed to break the board today. Based on some of the advice here I tried removing wood opposite the weak side of the limbs that were twisting. That didn't seem to do anything to fix the twist so I took a heat gun to the bow. I'm sure now that I made a mistake with the heat gun because I applied heat to the back of the bow instead of the belly. When that still didn't seem to correct the twist I just decided to restring the bow and continue with tillering to see what would happen to the twist if I was able to complete the bow. Well, I was pulling to my previous draw length when the thing broke clean apart in one diagonal break that ran from one side to another of a whole limb. Not sure if  the break ran from the weak side or the strong side or if I made the back fibers too brittle with the heat gun. The piece of wood I was working with was from the edge of a plain sawn board so the grain orientation was actually looking like bias ringed grain versus the typical decrowned pattern you see with plain sawn wood. Now I'm thinking I will just cut a section smack out of the middle of the decrowned section and essentially try to work it down to one ring and see if I get any better results that way.

[George Tsoukalas]

Patience is the bowyer's #1 tool, kilted celt. The  method I described to you would have worked provided you were able to discern the weak from the strong side. I know because I've used it countless times on straight staves where I caused the twist. I exercise the wood at short draws frequently too. I have not had much success removing prop twists on any wood with heat. But you learned something hopefully. Jawge

[sailordad]

i made a hick board bow that had a little twsit in it on one limb when braced.
thickness was even.i left it alone as it never got any worse when the bow was drawn
so i figured no harm no fould and just left it be,is shot nice so wh cared,not me.
i figured it gave the bow some character

you probably should have waited acouple of days after using the heat gun too
it gives the wood a chance to rehydrate some after being heated up