Heat temper bow belly debate

[Jomohr84]

Howdy guys,

I have read all I can find on all the Trad archery sites about tempering bow bellies, specifically with a heat gun. And there seems to be no consensus as to what is the proper method.

 I know that different woods take heat tempering differently, but I'm interested is white woods. I see some prefer to get the wood dark brown, some like it golden, and yet others want no color change at all. Some hold the gun in one spot, others move it back and forth. Some hold it 6" above the limb, others, 1" above.

So is there really a right or wrong, or is it about getting the heat to penetrate deeply and change the cell structure, and the color really doesn't matter? That's what I'm starting to think. As long as the wood gets evenly heated and gets real hot, color doesn't matter. Any thoughts?

Btw, I just attempted my first tempering on a red oak board bow last night. It was freshly tillered, not shot in yet. 46# @ 28", 1 1/4" set. Clamped it straight and used the heat gun about 30 min each limb, got it light brown on the belly. Came out of the clamps pretty straight his morning. Guess we'll see how it works. If it gained a few pounds and stayed straight, I'd be pleased. The belly got kinda shiny so it looks like something changed there.

[okie64]

I think the main thing is that the heat penetrates deep into the wood and doesnt just scorch it on the surface. The only whitewoods I have heat treated are hickory, hackberry, and ash. Hackberry and hickory worked great, and the ash worked ok, not nearly as good at holding the induced reflex as the other two. Ive tried all the different methods you talked about in your post and the one that works best for me is putting the heat gun in a holder about 3 inches away from the wood and let it sit there for about 4-5 minutes or so or until the wood starts changing over to the dark brown color. After the wood starts changing to the dark brown I move it up the limb an inch or two and start over. It takes a while to do it this way but in my experience thats the best method. Its much quicker to hold the gun in your hand and move it up and down the limb 6 inches at a time but I dont feel like it works as good that way. With osage I hold the gun in hand and move it but Im just doing it to reflex the stave, not heat treat it, osage is strong enough in compression that it doesnt need to be heat treated the way whitewoods do. Hackberry is pretty amazing when it is heat treated, its the only wood Ive heat treated that had absolutely no springback when unclamped off the caul, it held its shape perfectly. That my 2 cents for what its worth.

[Jomohr84]

Thanks for the insights! I think i'll experiment and try your method on the next white wood bow I make, and see the difference between the two. Don't think I'm gonna heat the next bow, since its gonna be hickory backed bubinga, I think i'll leave it as is. I do plan to Perry reflex it, and am wondering if tb3 and clamps on a form is all I need for that? No heat right?

[okie64]

Yep tb3 and clamps are all you need for perry reflex. Just make sure you have a good tight fit on the joint when using tb3, it is not a gap filling glue.

[Jomohr84]

Great, thanks for the advice, can't wait to start making better performing bows.

[Dan Landis]

I've had good success heat treating hackberry and hop hornbeam.  I use the same method as Okie,I also use a mixture of gum turpentine and tung oil brushed on liberally while the wood is hot.  I usually like to wait until tillering is almost complete before tempering....Dan

[Pat B]

Marc St Louis wrote a chapter in TBBIV all about heat treating(tempering) bow bellies. I've used it successfully with different whitewoods and osage and locust.It seems to work best with whitewoods and will increase the compression strength of them.

[Black Mockingbird]

I will floor tiller a stave till there is only 5-10 pounds left,and then heat treat it,and ill shape and correct it if it needs that as well during the tempering. I believe its best to temper wood before it starts to take any noticeable set. I temper it like okie desrcibed. Then ill clean it up with a scraper and sandpaper while also checking my floor tiller(which usually doesn't change,it just increases the poundage),so ill reduce a lil bit more weight then brace it and finish tiller. And ill usually have some color and markings from the temper left after I finish the tiller....some folks will heat treat multiple times,but in my opinion its overcooking the wood and increases the chances of ruining your stave. If done the way I do it ,it only needs done once.