How long to stabilize moisture content after heat treating

[Ippus]

I'm working on a red oak board bow, trying to bring the poundage up a bit.
-At first tillering it was around 36# @28" (I'm tillering to 30", where it was ~41#). I want to bring it up to a bare minimum of 40# @ 28".

So, I shortened it up a little.
-It was ~66" ntn (didn't do the best job measuring).
-I took a bit off and adjusted the width taper. It's now 63.5" ntn. I have the limbs tapering from 1.75" at the fades to 3/8" tips. 8.5" of non-working handle should give me 55" of working wood.

Just clamped the new nocks today.
I also toasted the belly and added just a teensy bit of reflex (with my wife's new heat gun... which she got for cake decorating and hasn't had a chance to play with yet... #inthedoghouse).


But anyway... it's my first time using heat this way, and I seem to recall reading something in TBB about waiting a certain amount of time after treating with dry heat to allow the moisture content to stabilize before you re-tiller it. I cannot remember how long they said. The nearest copy is in the local library, and I haven't gotten down there recently.

Anybody know?

[Jim Davis]

No doubt I'm in the minority ( I was born there and it seems like home:) but as soon as the wood has cooled, I start back to work on it. My thought is that the heat has only effected the belly, has hardened it and it will be in compression. Can't see how rehydrating will help that.

[Pat B]

Depends on your location. In humid areas like where I live I give a bow a few days before stressing. Whether or not it's necessary after getting that far on a bow I'd hate for it to blow because I was impatient. As you see, Jim has a different view. That's what makes the world go round. 

[Ippus]

It's generally pretty dry here. I'm in Southeast Idaho, which is high and semi-arid (native flora is mostly sagebrush and juniper), about 4500 ft.

[Badger]

  I go right back to work on the bow after it cools off also. I have never noticed any problems or surprises doing this.

[PatM]

The concern is that you may have dried the back out to a degree that will put the wood in a state of lowered tension strength.

 A little patience goes a long way, even if it actually wasn't needed.

[DC]

I leave them overnight if I can stand it. I've weighed them right after heating and then again the next day and noticed no weight difference. I do try and arrange my day so that heat treating is done in the late day so it's easier to leave overnight.

[Ippus]

Well, I guess the good news so far is that sounds like even those who advocate waiting are talking on the order of overnight or a day or two... given that I probably won't have significant time to devote to it again until next weekend, that shouldn't be much of a feat.

I was afraid we'd be talking weeks, like when a stave is curing. 

[Mo_coon-catcher]

I usually let mine sit on the form until the next day. Atleast for me they seem to hold the shape better if I let them sit for a while longer after they cool. Though if I’m just holding them straight so they don’t warp while heating I’ll pull them off as soon as they’re cool. It’s usually black locust and hickory I work with so I don’t know if other woods will behave differently.

Kyle

[Selfbowman]

I live in central Texas pretty humid but not like Seattle. I have heat treated and shot the bow the same day. It don't hurt them here. Never been known for patience but bow making has learned me a bit of patience. I also do it while I straighten the bow . Arvin

[High-Desert]

I live where summer humidity sits between 15-30%, I usually wait till the next day, only for cooling purposes because waiting 2 weeks wouldn't hydrate the bow anyway at these low moisture levels, and haven't broke a heat treated bow yet.

[Springbuck]

  I just broke a roughed out bow, that should have been a fantastic, high draw weight Mollegabet a few days back.  It was 70" long, 3.5" wide, low crown, and roughed out to good starting dimensions before I heat-treated it and fixed some lateral deviations.  It took two extensive trips to the heating caul and set-up to get it to all stay right, so I did cook it pretty good.

I basically was floor tillering it against my knee when the back just snapped like elm almost never snaps. One big transverse crack that went one thick growth ring deep and lifted a lengthwise shake-split between back ring and the next one down.  No insect damage, and the stave had decent treatment during harvest, drying, and storage.

My only guess is that I had really dried it out over those  couple days I was working it with heat.

[Ippus]

For further developments on this bow: http://www.primitivearcher.com/smf/index.php/topic,60128.0.html

[Stick Bender]

If it's a static part of a limb I heat treated for a minor corection I usaly only wait 1 hour but if I treat the bending area I usaly weight 8 or 9 days maybe I'm being to conservative but usaly have 2 or 3 bows going in different stages so the time doesent bother me and I know the bows rehydrated.