Primitive Archer
Main Discussion Area => Bows => Topic started by: eastcreekarchery on November 11, 2020, 01:26:32 pm
-
How should i heat the limb of a bow for taking out propeller twist? do I heat the back or belly or sides or everything? I know how to hang a weight on a clamp attached to the bow to twist it out but my question is how to heat the limb before you do that. Thanks!
-
I take it out when I heat treat. I will use a shin wedge of a softer wood and out the the clamp on the high side of the twisted limb. As I heat up the limb I will slowely crank down the clamp until I twist it about 25% further than I needed to move it to get the twist out. I do this a the same stage I’m putting in any reflex I’m wanting and any side bend that needs to come out. This works very well for black locust. You want to heat it slow enough you can feel the warmth on the back while heating from the belly. This will make sure the wood is hot all the way through. Once it is moved and clamped in place I move the heat gun much closer and get a mild scorching to the belly. When I do this I generally get the wood to stay where I want it. Sometimes too well and I don’t get the amount of spring back I expected.
Hope that helps,
Kyle
-
Have you braced the bow yet? Some twist won't hurt anything in a selfbow. You can also tiller the twist out so at full draw the limbs are straight.
Like Kyle said, take it out during heat treating if you plan to do that. Never heat the back of a wood bow. The heat will make it brittle weakening it's tension strength.
-
So long its not a string contact recurve, I dont worry about prop twist anymore. It doesn't hurt a thing.
-
How much twist?
-
Bring the stave to floor tiller . Put it on a form. With a heat gun start from the riser both ways, and heat ,and clamp as you go toward the tips lining the tips to the middle of the riser. You can take most of the twist out as you go, and at the same time.. Then give the belly a good heat treat to hold what you have.
-
Like this, heat only the offending area, this is done before floor tiller. if the bow is done, put the limb in a vise after the twist, heat the offending area and twist the handle in the opposite direction with your hand, just a tweek. Check your work and repeat until you have the limb straight. Let things cool and proceed.
-
After some thought I dont think this stave will need the twist taken out. Ill keep these suggestions for future use tho. Thanks!