what is belly tempering?

[dragonman]

What is all this talk of belly tempering, this is something I know nothing about (one of the many things). I presume it involves heating the belly!!! but what with and for how long, and how effective is it?? also, can it decrease the bows life span? and can it be done on all woods? In otherwords, when and how should one attempt belly tempering? I would be very interested to hear from experienced belly temperers if they would kindly like to share their wisdom. Especially with regard to how effective it is

[Justin Snyder]

You heat the belly of the limbs with a heat gun until they begin to scorch or turn darker.  It increases the compression strength of the belly.  It isn't something you need to do for a good bow.  However if you come in a little under weight or if you want to increase the performance a little you can by heat treating the belly and flipping up the tips. It will not fix a bad bow, but it can help a mediocre one if done right. 

[JackCrafty]

When I first heard the term belly tempering (on another forum) I thought it was a gimmick....a fancy way of making a bow more complex and "cool" and maybe even to make the bowyer seem more of an "expert".

Well, it turns out that belly tempering works well if you do it right.  How do you know if it's working well?  How do you know if you are doing it right?  Ah....very good questions.  Answer:  practice, patience, and cold hard data.

There are several people who temper their bows (on this forum).  The only advice I can give is that it is a technique that can make or break a bow (literally).  Be careful with belly tempering.

[dragonman]

I don't have a heat gun, and i feel a bit ignorant, but I don't know what one is either? How dark should the wood turn? could I use the hot embers of a fire or the hob of an electic cooker ?

Does any one out there have any photos of properly tempered wood? I would appreciate your efforts to post them if you do.

[Justin Snyder]

Marc did a great article on it for the magazine a couple of years ago.  If you can get your hands on the back issue it will be well worth it.  He posted some of the pictures if you care to search for them.  Justin

[Jesse]

Im no expert but have played around with it and it does work. an electric burner works great. A heat gun is basicly a really hot blow drier that is hot enough to burn the wood. From my limited experience you simply move the bow over the heat source until it just starts to turn color. careful to heat even so the tiller doesnt change. It can be used also to put in reflex by bracing the bow backwards and doing the above or putting it in a form. Not recommended for glued up bows. I would check out the article I need to as well as my knowledge is limited.

[dragonman]

Thanks for the imput, I'm gonna look up the article and photos. I think the best would be to practice on some scraps of wood first

Jesse-S ,  that sounds interesting, if it can put in a reflex, then it must be  effective

[adb]

Marc St Louis wrote a whole chapter in TBB Vol 4 on this very subject, and it's worth the price of the book alone. Check it out at horsefeathersranch.com.

[shamus]

Mark St.Louis has a detailed chapter on his heat treatment process, and I coverd it in my reivew of TBB4 on my website.  It 's a fascinating chapter. I first read about heat treatment in a Ye Sylvan Archer article: Heat Treatment of Wood by Wm. A Joy, October 1936.I do believe that heat treatment does something to a bow. What exactly heat treating does to a bow is still open to debate, as all attempts to explain the affects of heat treatment have been anecdotal rather than scientific. Does heat treatment merely reduce the moisture content or does it do more? But it is an an excellent chapter by Mark St. Louis.

[dragonman]

thanks shamus I'll check it out