Heat bending osage

[osageknot316]

Greetings all, I have just built a form for heat treating reflex into my osage bow. I seem to cause belly cracks on the belly (that go against the grain) whenever I try heat bending reflex in the handle area in my osage bows. I coat it with wild boar lard prior to heat gunning it. I should mention that I heat treat the belly in the floor tiller stage. Is there a way to prevent this on my next bow? Any advise is greatly appreciated.

[JW_Halverson]

You may be heating too fast and trying to bend before the wood is ready. When I heat a handle to make corrections, I spend a good 15 minutes slowly getting it up to temperature with the heat gun before I put any strain on the wood.

You may also want to look into steaming.  I recently picked up a $5 garment steamer at a second hand store. It was pretty gunked up with mineral deposits, but 25 cents worth of cheap dollar store vinegar solved that issue. I have found that you can get osage wood moving pretty easily with steam.

[superdav95]

You may be heating too fast and trying to bend before the wood is ready. When I heat a handle to make corrections, I spend a good 15 minutes slowly getting it up to temperature with the heat gun before I put any strain on the wood.

You may also want to look into steaming.  I recently picked up a $5 garment steamer at a second hand store. It was pretty gunked up with mineral deposits, but 25 cents worth of cheap dollar store vinegar solved that issue. I have found that you can get osage wood moving pretty easily with steam.

Yes JW.   I was just going to suggest steam as well. I use a wallpaper steamer and I too have found it work particularly  well for Osage on thicker portions for corrections. 

[Muskyman]

I’m not a patient person and I’ve not had much luck with a heat gun. Had probably the same results as osageknot but, I’ve done much better with steam. Usually one limb into my aluminum downspout with one end taped off and a rag into the other. If doing the handle put a rag in each end and get my steamer going and steam about an hour. I can wait on that where I end up going to fast with my heat gun and end up with a bad result. I usually have a good plan as far as where I want to bend and how much figured out before I start steaming. Clamps, shims and anything else I will need ready to go. Once you take it out of the downspout or whatever you use to steam it you need to get on with the clamping/bending etc. you’ve got time but just need to move fairly quick.
Good luck with the next one.

[Pat B]

On a thicker handle area I'd use steam and give it plenty of time for the heat to penetrate completely. On limbs I use dry heat with veg oil and never had a problem. For curves like on recurve bows I used to use dry heat and oil but did have cracking there so the next recurve I make I'll use steam for it.
 I generally wait until later in the process before tempering the belly and usually as I'm correcting alignment problems.

[Pappy]

I rarely do any tweaking or bending in the thick part of the handle area, I do most of my alignment work with the limbs if I have a problem with string alignment. Violating/grain rings and such in the none bending area isn't a problem so I try to get that part straight and how I want it in my lay out. 
 Pappy

[Gordon]

My experience with heat bending is: Steam - bend quickly; Dry heat - bend SLOWLY while maintaining heat

[Pappy]

That's been my experience also Gordon, being careful with not getting to hot, just enough heat where it bends easy with out a lot of force. 
 Pappy