Boiling Wood

[Radar67]

Hello All,
    I've been doing a little research/curiousity on the net. I ran across this site Boiling Wood
about boiling wood to get it to dry faster with less cracking. Has anyone had any experience with this process? I'm considering giving it a try on a couple of peices of turning wood to see how it turns out.

Stew

[brdmkr]

Stew,

I have never heard of such.... BUT I have some wood I'd like to try.  I figure, why not?  However, I can't really see how this would speed up drying.  I will have to go back and read the entire discussion, but that one confuses me.  One thing I could see happening is bug killing.  Of course, this would be REALLY tough to do on a large scale.  It also wasn't clear to me if boiling is on green wood or on air dried.

I have some logs to saw this weekend .  I'll perform an experiment and post.

[dundee]

We have a species in New Zealand (Red Beech)---no one has been able to dry the stuff, our Forest Research Institute have written books of how to dry it--none were at all succesfull, they even suggested boiling to stop case hardening / cell collapse and help with final drying after stickering, all failed hence many millers who mill the beech do not drive mercedes and do struggle to make a honest dollar.

Maybe the species you guy's are milling could be different, to boil on a production scale would be costly taking into account the energy and the leaching of tannin that has to be dumped after you have "boiled" a zillion BF /M3

however, thanks to a certain member of this forum, his brilliance has solved the red beech problem

Richard

[woodbowl]

I heard old stories around here of boiling the dough bowl after it was hewed out to minimize cracks. I know a fellow that says he did it and it works. I tried it once, but couldn't tell if it made any difference or not.

[getoverit]

I remember seeing Roy Underhill do some boiling of wood a while back, but it seems like it was birch that he was boiling, and the reason he boiled it was to help with bending the wood afterwards. He was making rocking chairs with it, and once "set" in the curve he wanted, the wood was left to dry and would stay in that shape.

Doesnt the large scale mills use steam to help speed up the drying process in their kilns?

[woodbowl]

Doesnt the large scale mills use steam to help speed up the drying process in their kilns?

I've heard that steam causes the wood to dry from the inside out.  ?? ?? ?? ??

[Radar67]

It also wasn't clear to me if boiling is on green wood or on air dried.

In the first line, the author says green wood. He also stated that this process was more for hard to dry woods, if it was a stable wood, you didn't need to boil.

My theory on this speeding up the drying process is this, during the boiling process the water and sap in the wood is transformed to steam. The steam more easily exits the wood while it is boiling for the hour. After the wood is removed from the boiling water, as it cools off, the water vapor continues to exit the wood. Once the wood has cooled off back to room temperature (for lack of a better term, maybe ambiant Temp?) the moisture content of the wood is much decreased in the center thus speeding up the drying process overall. Just my thoughts on this, I may be way off base.

I never thought about bug killing, thanks for pointing that out.

I agree that this process would not be good for production, but for the hobby sawyer/turner, it could increase production.  I would think a vacum kiln would be the way to go for a true production scale.

Olen, do you use any type finish on your dough bowls?

Stew

[woodbowl]

Sometimes. ........... but I like them all just to be different. Laquer, Acrylic, Enamel, tung oil, olive oil, danish oil, shaved wax and mineral oil, nothing ect.

[Radar67]

Basically what you have on hand if you want to finish?   

I've been using straight parafin wax or arrow wood finish. I'm about to try tung oil and later, a tung and parafin mix.

Stew

[jimF]

Boiling wood will weakens it and changes the color similar to weathering.  If you boil it in water the wood will be saturated and by the time it cools down when taken out it will not have lost a significant amount of water. 
Some have boiled wood in oil and obtained dry wood but then it would be oily.  This too would degrade the wood.

[TW]

Almost common practise over here:
Boiling in water is used by hobby carvers in order to lessen the risk of stress cracks in birch burls. It is done with green wood. They boil it for many hours. Then the wood is airdried slowly. I think the boiling lessens the internal stresses in a similar manner as steam bending.

I have not tried it myself but I have seen it beeing done.

[Curlywoods]

Lotsa people boil Madrone burls, as if you don't it will crack and split into a big mess.  Boiling is the only way to dry this stuff if you intend to do anything with it later on

  I had a supplier in Oregon that boiled crotch wood pieces and swore that it had near zero defects after he did this and dried it.  I have no first hand experience, but he said that is what his dad taught him and he said that his dad learned it from his grandfather.  Maybe something to it, but again I have no experience, just heard of others doing it with success.

[Bob Smalser]

For centuries pipe makers working with Mediterranean briar have boiled it immediately after harvest to remove bitter saps and oils.  Then the better makers air dry the blanks for at least three years before shaping pipe bowls.

[Reddog]

I can tell you when we steam green ash to bend it. It really dries out fast. Seems to remove the sap. Do not know about cracking, as we bend it into forms.  my .02

[Burlkraft]

Stew,

I have boiled a lot of green bowls. It works very well on burl and curly woods of most species. I have not had the same results with straight grain maple or cherry. Why?? Heck I don't know. Recently I have been soaking green bowls in denatured alcohol. I have had excellent results with that. I have experemented with soak times. About a week is good for most except boxelder. That seems to dry down to nothing in a day or two. I have some cherry and maple burl bowls that were really wet when I turned them and they have been soaking for a month. These things are very dry and they did not warp at all. I took one out the other day, a maple one, and it was at about 3/4 inch thick. I finish turned it to almost transparent and then I linseed oiled it. When you hold up to the light it almost looks like Norflok Pine. I have some cherry in there to. It seems to be in the same condition. The alcohol soak is a lot easier than boiling and I seem to get better results.

[metalspinner]

Hmmmm.... I might just take the crawfish pot out and have a test.

[Radar67]

Burlkraft and all,
     I found another link that looks promising as well, Soap Solution Go down to the section titled Experimental New Treatment for Wood. The results this guy has achieved sound good enough to prompt a trial of my own in the near future. I also plan to try the boiling process as well. I'll make sure I document and photograph well so I can report my findings here. 

Stew

[beenthere]

If anyone is going to do some 'experimental' runs with boiling, and take pics, then hopefully they will use some matched pieces, boiling some and leaving some with conventional drying for a good comparison. It'll make explaining the results much easier and much more useful. Matching a piece from the same log would be most convincing and helpful.
Sure hope we can see some results.

[Radar67]

I've got a small cherry log (about 4 inches) and some pieces of beech (about 8 or 10 inches). I think I will try it out on them and document it. It will take a few days to get everything together.

Stew

[Den Socling]

This is a great thread.    It would be great to have a method to dry any difficult and beautiful chunk for a turner. It's Mythsbuster's Forestry Forum. Boiling, alcohol, soap or what? Experimental pieces with 'control' pieces. That's what we need.