Help… Heat Treating Osage for Dummies

[perry f.]

So I built an osage bow that came in about 10 lbs under weight. I know I should probably leave it as is, but wanting to learn and try new things, I was curious about raising the draw weight by heat treating the belly with a heat gun. Can someone walk me through this process? Thanks!

[Pat B]

Perry, here's how I do it...
 I clamp the handle of the bow to a form then heat the first 6" or so at the fades of one limb, holding the heat gun about 1" from the belly moving it back and forth along those 6" until I get color, clamp it and move out another 6" and continue on heating and clamping until that limb is done. Be sure your clamps are padded as not to dent the hot wood. I then go over the entire limb to reheat it before moving to the next limb. Then I go to the second limb doing the same. I leave the bow in the form overnight to cool.
 I doubt you'll get 10# increase in weight just from the heating. Adding reflex while heat treating will give you a little more weight as will flipping the tips a bit.
How long is your stave and draw length? You could also pike the limbs an inch or two, if the bows length allows to increase weight.

[perry f.]

Thanks Pat. My bow is 64” tip to tip. It already has some pretty aggressive curves at the end of the limbs, I was experimenting on those as well. I guess I could still reflex the remainder of the limb. I only applied heat to the tips. I hadn’t built a bow for a while and I’m not very experienced. I believe I left it on the long string too long. I haven’t shot it yet but have it tillered out to 28”. I draw 27.5” I tried putting a picture on here but haven’t figured out how to on this site yet. 

[Will B]

I do pretty much what Pat does. I have a reflex form that allows me to heat treat and add reflex to straight limbed or recurves bows. I keep my heat gun stationary (it is attached to an old microphone stand) 3-4” from the limb and move it after I start to see some color change. A picture of my form with a completed recurve bow is provided. Good luck

[perry f.]

Will B, have you experienced any success in raising the draw weight? Thanks

[Will B]

Perry, yes I have seen a weight increase but I honestly don’t remember how much. Definitely worth a try.

[TimmyDeNorCal]

Perry,

Does your bow bend through the handle? If it is a bendy-handle bow you could most likely pike an inch or so off of each end and still be able to safely draw 27.5”.

I built a 62.25” Osage flatbow with a semi-bendy handle that easily draws 28”.

Also - from what I have read through many posts in this amazingly informative forum is that most people only experience slight draw weight additions from heat-treating an Osage belly. I heat-treated that 62.25” Osage flatbow of mine and picked up maybe just a few pounds of draw weight.

Now that I think about it a little more, I was just about in your exact same shoes (other than maybe your handle...) - I came in underweight on about a 64.25” Osage bow. It was my 1st stave bow & I finished her out at a disappointing 38 pounds @ 28”. My steps from there were piking an inch from each tip, heat-treating the belly...and then just getting lucky and having the bow gain weight from drying out (cuz I mistakenly thought that the stave had reached its equilibrium moisture content-wise). After I piked it 1 inch I gained the fairly typical 5# of draw weight...and then after I heat-treated I gained 2 or 3# more...and then after another month or 2 I gained about 7 more pounds from reduced moisture content. That Osage bow ended up being 53# @ 28” (although it now stands at 49# @ 28” because I have tweaked the tiller a little and thinned out the tips twice).

So, all that being said, and assuming your wood was dryer than mine when you started turning her into a bow, I would think that you could likely add 7-8 pounds of draw weight by piking an inch & heat-treating. And maybe the newbie bowyer gods will look favorably upon you like they did me and grant you added draw weight (without the added set that tillering a wetter-than-ideal wood bow usually provides!!)...

[Marc St Louis]

I made a couple videos on my method of heat-treating many years ago, warning the sound sucks.  You can find links here

http://www.primitivearcher.com/smf/index.php?topic=23338.msg314569#msg314569

[perry f.]

Timmy, my bow doesn’t bend through the handle.
I ended up heat treating and introducing some reflex. I left it alone for 2 days and strung it up last night. The tiller was horrible. After retillering, the draw weight jumped from 41@28” to 47@28”. I am pleasantly surprised. Thanks for all the information here. I appreciate it

[BowEd]

I do pretty much what Pat does. I have a reflex form that allows me to heat treat and add reflex to straight limbed or recurves bows. I keep my heat gun stationary (it is attached to an old microphone stand) 3-4” from the limb and move it after I start to see some color change. A picture of my form with a completed recurve bow is provided. Good luck

Form looks familiar.

[Don W]

Here is the last hophornmbeam i did. I had snapped a few pictures.