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Alcohol drying wood
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Joined: Fri Apr 25, 2008 8:51 am
Posts: 44
Location: Lake City FL,
Post Alcohol drying wood
I Have been playing around with drying bowls with denatured alcohol. This all stemed from an artical that I read. I submerg the peace for two days then remove and let dry for about 30 min. Then wrap the outside with news papper. Place upside down on a wire rack and check the smell every few days. I am on the third attempt and haven't had any checking but have had some movment. The wood I used is spalted croch red maple. Half of the the blank was dry as a bone the other half was green, really green. This is where I think all the movement came from.
Has any one tryed this method? I am not sure if I am doing this 100% correct. I cant find that artical again.


Fri Apr 25, 2008 11:58 am
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Joined: Wed Aug 30, 2006 6:31 am
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Article is here http://alcoholsoaking.blogspot.com/ If you believe that the laws of physical chemistry have been repealed, continue to soak at your expense. The real answer is to control the rate of loss from the exterior to one which allows replacement by moisture from the interior to keep the fiber from collapse and checking. Easy enough to do, though you still have to deal with the reality of the wood. It will warp from the FSP (Fiber Saturation Point) on down to atmospheric equilibrium in a predictable fashion, and in fairly predictable percentage. As long as you know this and make allowances for it, you can produce a dried blank which will allow a re-turn to circularity without alcohol.

Note, as you read the article, that the proponent of "the method" presents no controlled comparison. I, and others who have had the courage to chide the emperor on this point of attire, have done so, and there is no demonstrable difference in dry time nor distortion, exactly as physical chemistry suggests.


Fri Apr 25, 2008 3:21 pm
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Joined: Mon Jun 26, 2006 10:43 pm
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Location: Vacaville, CA
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I have had a great deal of success, over-all, using the alcohol drying method. Also, as you mentioned, I did experience some checking from time to time, but no cracking, splitting or other horrible results. As you point out, the movement in the wood as the alcohol evaporates has always been a factor in my exprience but movement in any wood using any drying method is, again in my experience, typical to greater or lesser degree. I'm not a chemist, so I can't speak to the issue scientifically. All I know is that conventional drying methods - although they do work - have resulted in horror stories more often than the alcohol drying method. I don't care if that defies the laws of physics; as long as I'm pleased with the results.

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Fri Apr 25, 2008 9:01 pm
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Joined: Wed Mar 19, 2008 12:34 pm
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Location: California
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What is worrysome about this is the likelyhood that one is drying the wood at the surface but not at the center of the block. This will produce surface cracks. Generally, one wants to slow down the drying so that moisture in the center has time to travel toward the surface. Any system used to shorten drying time is likely to increase this problem.

First turning is the only method I know of that safely shortens the time from wet wood to finished bowls. In addition to shortening drying time, wood movement is accomodated avoiding cracking.

Malcolm Smith.

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malcolm


Sat Apr 26, 2008 10:35 am
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smith wrote:
What is worrysome about this is the likelyhood that one is drying the wood at the surface but not at the center of the block. This will produce surface cracks.


Not really a player, since penetration at 24 hours is perhaps an eighth of an inch on end grain with open-grained woods, half that, as indicated by a dye on close-grained types. Mixing of alcohol and unbound moisture, given room temperature at ~65 F and no agitation is minimal as well. What little "flash" drying the surface gets seems to be only enough to case-harden it modestly, similar to the effect you get from pressing a bit too hard when sanding. I never soaked beyond 48 hours in my experiments, but the extra day produced perhaps an additional 16th of an inch, so the wood scientists are probably accurate in their assertion that the inverse square rule applies.

If you're in a hurry, game the average shrink figures found in the FPL Wood Handbook for the species in use when you hollow. Half the thickness dries more than three times as fast.

I like to blast compressed air through the wood to help unbound moisture work out and throw centrifugally. Gives me an edge in the battle against mildew, which can be a real problem if the RH is high. When doing warp-and-go bark up pieces in white woods, the last thing you need are mildew spots. For a "whenever" piece, I don't bother, because re-turning will generally remove the black spots.

At ~1" thickness on woods like cherry or birch, drying at 70% RH for a week and then dropping to 55% will allow equilibrium in a month to six weeks with no air blast. At ~3/4 you can take almost two weeks off the time if you're in a hurry, though you sacrifice a bit of redesign capability. If you add 10-15 degrees in warmth you can do a bit better than that with little risk. At least that's worked on a couple thousand pieces over the last twenty-five years.


Sat Apr 26, 2008 7:58 pm
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Joined: Fri Apr 25, 2008 8:51 am
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Location: Lake City FL,
Post Alcohol drying
WoW, MichaelMouse you seem to feel strong about this subject and that can be respected. But I can't comprehend half of what you said. as for in a hurry, no I was just worried that the bowl being half dry and half wet would destroy it. You are deffinetly on top of your game and I can see that I can learn alot from you.

Nutturner, How many different typs of wood have you tryed with this method?
I will post some pics of the bowls monday they turned out good I think.
I am intrested to see what others say about it


Sat Apr 26, 2008 9:18 pm
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Joined: Mon Jun 26, 2006 10:43 pm
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Location: Vacaville, CA
Post Re: Alcohol drying
turkey wrote:

Nuturner, How many different typs of wood have you tryed with this method?


Plum and Rosewood

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Sat Apr 26, 2008 9:37 pm
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Joined: Wed Jan 23, 2008 9:23 am
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MM is well known for his opinion against alcohol drying.

I've used DNA for drying wood for years and find that it works. I've used it on holly, maple, walnut, cherry and a few other types I'm sure I'm forgetting.

But don't take our word, try it for yourself and form your own opinion.


Sun Apr 27, 2008 7:21 am
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Joined: Wed Aug 30, 2006 6:31 am
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Post Re: Alcohol drying
turkey wrote:
WoW, MichaelMouse you seem to feel strong about this subject and that can be respected.


I feel strongly about science, even though I know the power of the placebo in medicine, and the halo effect in politics and turning!

If you're looking for some understanding, go here and get the free book, or if not a broadbander, at least chapters 2 and 3. http://www.fpl.fs.fed.us/documnts/fplgt ... gtr113.htm Lots of good information in there. Just looking at fig 3-3 can be an epiphany. Not only does it confirm what you see on the shelves at the home center, it gives you information you can use to keep your turnings within re-turn dimension when you combine that knowledge with the figures on average shrinkage. Remember as you look at them that the wood moves toward wood, not air.

To relate the assertions on alcohol to the common experience, look at every oil finish you've used, the gasoline in your tank, and the booze in your glass. All have miscible liquids involved, and in every case the one with the lower boiling point evaporates without affecting the rate of the higher boiling point solute. They've been produced or enriched through a process known as differential distillation which operates on the principle stated. Either we have a serendipitous exception to the rule for woodturners, or it's a bad assumption which can be easily disproved by proper experimental method.

Look at those old wooden barrels showing up an home and garden centers this spring to see if soaking in alcohol for years has stabilized the wood. While you're at it, think of how dumb a brewer, vintner or distiller would have to be to store his booze in wood if wood traded water for alcohol. People in the alcohol business don't dilute their potables.

The reason the soak "works" is because it would achieve the same result without the soak. The atmosphere is capable of holding only so much water vapor at any given temperature/pressure, so even if water tried to evaporate faster, it'd have no place to go.


Sun Apr 27, 2008 8:02 am
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Joined: Wed Jan 23, 2008 9:23 am
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Post Re: Alcohol drying
MichaelMouse wrote:
turkey wrote:
WoW, MichaelMouse you seem to feel strong about this subject and that can be respected.


I feel strongly about science, even though I know the power of the placebo in medicine, and the halo effect in politics and turning!

If you're looking for some understanding, go here and get the free book, or if not a broadbander, at least chapters 2 and 3. http://www.fpl.fs.fed.us/documnts/fplgt ... gtr113.htm Lots of good information in there. Just looking at fig 3-3 can be an epiphany. Not only does it confirm what you see on the shelves at the home center, it gives you information you can use to keep your turnings within re-turn dimension when you combine that knowledge with the figures on average shrinkage. Remember as you look at them that the wood moves toward wood, not air.

To relate the assertions on alcohol to the common experience, look at every oil finish you've used, the gasoline in your tank, and the booze in your glass. All have miscible liquids involved, and in every case the one with the lower boiling point evaporates without affecting the rate of the higher boiling point solute. They've been produced or enriched through a process known as differential distillation which operates on the principle stated. Either we have a serendipitous exception to the rule for woodturners, or it's a bad assumption which can be easily disproved by proper experimental method.

Look at those old wooden barrels showing up an home and garden centers this spring to see if soaking in alcohol for years has stabilized the wood. While you're at it, think of how dumb a brewer, vintner or distiller would have to be to store his booze in wood if wood traded water for alcohol. People in the alcohol business don't dilute their potables.

The reason the soak "works" is because it would achieve the same result without the soak. The atmosphere is capable of holding only so much water vapor at any given temperature/pressure, so even if water tried to evaporate faster, it'd have no place to go.


George
It's usually a academician who prefers to study studies and uses dogma science as a means to prevent advancements.

The study that you so enjoy flaunting as the finial word doesn't even cover vacuum drying. It is far from complete. I don't have the time to waste, but I do know Forest Products Laboratory has completed studies on drying wood with chemicals and alcohol was one they tested. Why don't you look for it, read it. Then actually try this method for yourself. Use all the controls you want, then report your finds.

BTW Alcohol is used to dampen wood so epoxy can penetrate into wood deeper making a better bond.


Sun Apr 27, 2008 10:36 am
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Joined: Thu Sep 07, 2006 11:22 am
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Location: Eugene, OR
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The drying methods topic comes up time after time. The most important thing in drying bowl blanks is to create a mini environment that you can control. If you dry the bowls too fast they will crack. If you dry them too slow, they will mildew. You can air dry, you can soak in DNA, you can soak in LDD (liquid dishwashing detergent 1/2 water, 1/2 soap), you can boil and or steam, you can microwave, kiln dry, vacuum dry, plastic bag, paper bag. All methods work. The one that works best for you depends a lot on your local weather/relative humidity. I use the LDD system. I did soak maybe 300 bowls in the DNA before trying the LDD. I continue to use the LDD. I did one test where I used 3 sets of bowls (madrone), cut to the same size and thickness (1/4 inch). One set was air dried, and the others got the soaks. I weighed each piece until they reached equilibrium. The results were identical, they reached dryness at the same time, 10 days. There was no difference in how much they moved. With the hundreds that I DNA'd and the thousand or three that I have LDD soaked, there is no measurable differences that I can see in success of drying or drying time. The only real difference that I have seen is that the ones that are DNA soaked are harder to sand out, and the LDD ones are a lot easier to sand out. I do turn green wood to final thickness, soak, let them dry and warp, then sand and finish. I haven't tested these methods with the turn thick, dry, then return method. Perhaps the thickness could make a difference in the drying time. I don't know of anyone who has done a comparison test of this. I have heard that LDD soaked bowls when done thick and returned cut a lot easier. The woods that I have tried with these methods are Madrone, myrtle, black and english walnut, butternut, big leaf maple, silver maple, elm, sycamore, apple, cherry, plum, pear, chinkapin, black locust, honey locust, osage, ash, cascarra, red bud, yew, hawthorn, and probably some more. As far as soaking times, I have soaked for 24 hours to a month on pieces that got lost in the solutions. Again, no difference. As far as penetration, I put one piece of sycamore in the DNA, and it soaked through the endgrain in about 2 seconds. Penetration will depend on the wood. Both alcohol and soap reduce surface tension. There is some pigment that is disolved in both solutions. After a while, especially if you are soaking dark woods, the solution can color what you are soaking. Then it is time to throw the old stuff away.

robo hippy


Sun Apr 27, 2008 11:34 am
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As indicated above, I have done the controlled experiments. I also report the results. Have you done side-by side experiments? Give it a whirl.

Might I suggest a proper control? Make your test pieces identical cubes selected from alternate positions along a squared stick. This will give you the same grain pattern, making your distortion figures most accurate. You can eject unbound water with compressed air to simulate the centrifugal throw, but that introduces a variable which can be difficult to weed out. You have to blast and weigh, blast and weigh to get similar weight, which would indicate similar unbound content. If you don't eject, there will be virtually no penetration, because the alcohol will have little air space to fill.

I think you are confused about the FPL, though I would be glad to read what you come up with. Says volumes to me to know that Weyerhauser doesn't use it.

Of course, you might be confused as to the source of the "drying" experiments. The Aggies have a good summary of conservation methods, some of which involve alcohol. http://nautarch.tamu.edu/class/anth605/File6.htm Is the place, but it goes against the assertions made on behalf of ethanol, because the only workable methods involve using water or alcohol as a method for getting higher boiling point liquids into the cells.

EDIT for the Hippy

As Madge used to remind us, dishwashing detergents contain a humectant - normally glycerol - to protect our cuticles. It is an alcohol - triol, actually - so it will mix with water even without benefit of surfactant, but, sad to say, it proves the opposite by its effectiveness in keeping the fibers expanded. It has a higher boiling point than water.


Then there are standard methods for preparation of tissue specimens to be embedded in paraffin which involve repeated baths in alcohol to dehydrate the material. IIRC, three or four, then a final in absolute were the norm. Dilution was the solution there, of course. Then to the microtome. Been a while, but if you want to put a bit of effort into learning, you could look it up.


Sun Apr 27, 2008 11:34 am
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Joined: Fri Apr 25, 2008 8:51 am
Posts: 44
Location: Lake City FL,
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Quote:
Look at those old wooden barrels showing up an home and garden centers this spring to see if soaking in alcohol for years has stabilized the wood. While you're at it, think of how dumb a brewer, vintner or distiller would have to be to store his booze in wood if wood traded water for alcohol. People in the alcohol business don't dilute their potables.


People in the alcohol business do dilute there Potables That is what makes it drinkable. It is stored in the chard wooden barrels for flavor. I know this from flavoring my home made wiskey. After the wiskey has taken the flavor out of the chard wood I use it to cook steaks or smoke a pig cause the flavor of the alcohol flavors the food. (Well now all of you know I am just another REDNECK)

Robo hippy
Are you saying you were able to dry all of these different typs of wood after they have been turned to final thickness with continous success? I will say, Iam intrested in methods of drying not the scince behind it. That said, I do feel that knowing how the method works is just as important as if it works. I want everyone to understand I am not and do not consider myself a wood turner yet. I am just some jo with a lathe trying to make a found passion come true so if not understanding what alot of this is please forgive me. I am intrested in what everyone has to say.

MichaelMouse,
That artical is intresting and I look foward to learning more.

Phllip


Sun Apr 27, 2008 5:36 pm
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Joined: Wed Jan 10, 2007 8:11 pm
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Location: Fort Pierce, Fl. USA
Post Alcohol Drying
turkey,
the alcohol drying that I have done has been on tropical woods from Fort Pierce and south. Wood still moved, just not as much. Drying is easier in our high ambient humidity and didn't save a lot of time with alcohol.
MM mentions the Texas A & M papers but doesn't mention that they used other solvents as well (unlimited money) and concluded that acetone was best for their purposes. They were preserving wood that had been under water for hundreds of years.
Once again, use the alcohol to save some time, but some woods will still move considerably, others just a little. Have fun! Keep turning and learning!
Don't believe the government propaganda! :roll:

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Sun Apr 27, 2008 5:43 pm
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Joined: Thu Sep 07, 2006 11:22 am
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Location: Eugene, OR
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Turkey,
If I didn't live on the other corner of the country, I would invite myself over for one of your barbques. Darn. As far as cracking, some woods are more prone to cracking than others. The fruit woods for example like to crack more than walnut, or maple. Madrone (One of our local woods) likes to start splitting when you fire up the chainsaw. Most of the time, because of our cool fairly humid climate, I will just put the bowls on the floor for a few days, then up on a wire shelf to finish. Any tiny crack in the wood will open up more. Any knot hole, or the pith (center of the log) will genrealy guarantee a crack. The feather pattern from crotch wood likes to split as well.

For the Madrone, I will put it in double bags. Even then, the failure rate is 25% or so, but it moves a huge amount. A round bowl can end up 10 inches long, and 6 inches wide, with height variation of 2 or more inches. With it, you just never know. This is a wood that a lot of turners will boil (1 hour per inch of thickness, cool off in the water, and then dry, some times coating with anchorseal). I don't like to boil because it will muddle the colors together.

You will have to experiment to find out what works in your area. Do try to find a local club, and ask around. You will find out that there are a lot of ways. A club is a good place to learn as well.

robo hippy


Sun Apr 27, 2008 6:30 pm
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