Boiling Bow Staves?

[DLH]

I thought I had seen a thread awhile back where someone on here was boiling a stave over a campfire with their friends. Now I can't find it I searched on the site and googled it too. I can't seem to find much on boiling staves except for inducing reflex. I was wondering if this would maybe help cut down on the drying time? I am not in a huge hurry just wanted to give it a try and was wondering if anyone on here has any experience boiling wood?

Thanks in advance

[Gordon]

I sometimes boil tips before bending into recurves. I don't see how boiling a stave could reduce drying time however.

[soy]

I am with gordon on boiling to bend but who knows maby the heat helps it to dry

[Pappy]

Never heard of boiling a whole stave,steaming yes and boiling tips yes. 
   Pappy

[H Rhodes]

I had good luck using steam to straighten a stave where the string could track, or to induce reflex at the handle or the tips, and I guess boiling has the same effect.  It doesn't make sense to me that it would speed drying, since you are introducing moisture into the wood.  If anything, it slows the process, at least a few days, since you will have to wait for the moisture from the steaming process to dissipate.  Just my thoughts.....  i am still pretty new at this stuff.

[DLH]

I have just seen where people boil bowl blanks so they could use it faster I didn't understand it either just thought someone on here might have tried it with some staves.

[Justin Snyder]

Steaming makes more sense. Steam is actually hotter than boiling water so it will heat the bow faster and it is a lot easier to create a chamber and fill it with steam than it is to try to find a pot of boiling water big enough to fit the bow in.

[Eric Krewson]

The way I understand it steaming or boiling drives moisture out of the wood. Think of it this way, when water turns to steam it increases in volume by 4000%, thats why steam engines work. When you heat a piece of wood to above the boiling point, the water inside turns to steam, expands by 4000% and has to go somewhere, which is outside the piece of wood, drying it out in the process.

Guess you can tell I spent all my working days in a coal fired steam generating facility.

[Slackbunny]

I'm a mechanical engineering student, and fluid mechanics is a key part of that. Based on what I know about water and steam, I would guess that Eric Krewson is right. That steam should force much of the liquid moisture out.

This also jives with my own experience. I noticed last week when I was steaming the twist out of a limb, that after it dried, the limb that had been steamed felt drier than the other limb.

Also I've heard of wood cracking after beeing steamed, could this be a result of rapid drying afterwards?

I'm going to send an email to my fluid mechanics proffessor. He's one of the best in his field and can probably lend something useful to this discussion.

[DLH]

It also boils the sap out of the wood if I understand it correctly the water will be pure black after being done I plan on trying it with some hard maple an sealing it like normal after it has been boiled. Think boiling would take away from the strength of the wood or change any of its properties?

[Slackbunny]

I'm guessing that boiling might be detrimental if it removes the sap. I'm guessing that the sap is key to the "curing" process.

I am setting up an experiment right now to test the effects of steam. We'll see how it goes.

[Gus]

Al Herrin Boils his staves for straightening.
Uses a piece of 2 or 3 inch Pipe, leaned over a fire to boil an entire limb at one time.

Gary Davis Steams whole staves in Stove Pipe for straightening.
And on his DVD says that it Seasons the Wood at the same time.

-gus

[Slackbunny]

I won't know for sure how things went until I get more data over the next few days, but the intitial results are encouraging.

I have used two pairs of freshly cut sticks from the trunk of a sapling as test subjects, I call them group A and group B. In both groups I steamed one stick and left the other as a control. Their sizes are not exactly the same but are very close, and I am using percent weight loss so the results are comparable.

In group A, directly after the steaming, the steamed stick had lost 3.7% of its weight. This was only seconds after the steaming was complete. The control had only lost 1.9% of its weight at this time.

In group B, directly after steaming, the steamed stick had lost 3.9% of its weight. The control had lost 2% of its weight.

The fact that the rate of moisture loss is nearly the same in both groups is a good indicator that this is an accurate test.

So it appears that steaming does initially decrease the moisture content of the wood. In fact it appears to double the rate of moisture loss over the 45 minute steam duration. I will continue to take weight readings of the specimens to determine if this significantly affects the overall drying time.   

I will update my results in an hour as the weight is changing rapidly on the specimens.

[Weylin]

John Strunk told me that steaming and boiling dried out the wood by forcing out the moisture. He said that the wood can be just as dangerously dry after steaming it as it can be from heat bending it.

[Carson (CMB)]

" for it's during that period immediately after steaming that an unprotected stave checks dramatically"  -Dean Torges, Hunting the Osage Bow. 

Just came across that statement after reading this thread.  Dean is referring to green staves being steamed prior to going on a reflex caul.  Just another indicator that steam and boiling increases drying of green wood.