Soaking roughed pieces in denatured alcohol....long story...

[Rob Wallace]

I just wanted to report on an alternate purpose for soaking rough-turned pieces in denatured alcohol. (Note that I will never use 'DNA' as an abbreviation for adulterated ethanol, since that acronym already has widespread acceptance for a VERY different chemical!).

Many of you will recall that "alcohol soaking" was popularized by Dave Smith some years ago to shorten the dry-down time for 'wet' rough-outs. After a while of experimenting with that method, I found that with the exception of a few species of wood (mostly "fruitwoods" in the Rose Family), the hassle of alcohol soaking was not worth the cost or extra effort, and I have since just used Anchorseal or paper bags to slow down the rate of simple air drying on my roughed bowls and vessels.

I did want to report an alternate use for alcohol soaking..... cessation of fungus activity. In mid-April 2012, I was given most of my next door neighbor's river birch by the tree crew who took down the tree - mostly 18-24" diameter log sections. They were stored on my driveway under "blue tarps" as I slowly whacked away at them when I could - but of course I never have as much turning time as I'd like, and at least half of them were actively spalting throughout the summer and fall. When the threat of snow came in December, I made log half sections out of most of them, and stored the decent pieces in my garage. On January 12th this year, I did a demo for the Des Moines Woodturners, and even though the wet piece of river birch log I used was fully frozen when I cut the round on the band saw, it turned superbly, and gorgeous zone lines and "shades of gray & brown" were exposed during my demo; just a beautiful piece of wood! I brought the roughed blank home from the demo wrapped in a plastic bag, needing to get it coated with Anchorseal and start it drying, but had forgotten about it for three days due to the start of our Spring semester here, and the "stuff" I had to do to get classes going. Three days after I roughed the bowl, I remembered that I still had to Anchorseal the blank and get it out of the bag. When I opened the plastic bag, I was greeted with thousands of fine, white fungus filaments covering the entire piece! I decided immediately that this was a good time to soak it in alcohol, and essentially "pickle" the living fungi. This worked REALLY well - I even put the alcohol soaked and surface-dried bowl BACK IN a plastic bag to see if any additional fungal growth was detected - but NONE after 4 days at shop temperature! I then coated the end grain with Anchorseal, and about ten days after the alcohol soak, the moisture content of the spalted river birch was below 15% (measured the tenon and rim with a Delmhorst J-2000 moisture meter; starting MC was over 30%).

Those of you with similar situations of having 'active growth' fungi in blanks you've turned should consider alcohol soaking, not necessarily as an aid to speeding-up drying, but a method that stops the continued growth of fungi to prevent further degradation of your roughed pieces.

Rob Wallace

 

[John Torchick]

I take it you buy the alcohol in large quantities. Where do you get your denatured alcohol?

 

[Rob Wallace]

John:

I usually buy it a gallon at a time at our local Theisen's (Farm Supply Store) - cheaper there than at Lowe's, Home Depot, or Ace Hardware. When Theisen's has their 18% discount bag sale, I can fit 3 gallons of Denatured Alcohol into one of their discount bags for even more savings. (I also use it routinely to mix my own ultra-blonde shellac for use as a sanding sealer.)

Remember that denatured alcohol can be up to 40% methanol by volume, so it should be considered 'toxic'. It can not only dry-out and de-lipify skin, but my understanding is that small amounts can be absorbed transdermally - keep it off your skin!

Rob Wallace

 

[MichaelMouse]

Cheaper answer, don't bag or anchorseal. That aside, white hairy mildew doesn't seem to discolor below the surface. Did you give it a scrape? The black stuff penetrates far enough to make white woods ugly, which is why my brief fling with anchorseal lasted less than a half gallon.

http://www.ehow.com/how_5626545_kill-white-mold-mildew.html

Both chlorine bleach and vinegar have worked for those who bag too close.

 

[Bill Boehme]

From what I have read about spalting in Hoadley's books and elsewhere (maybe the FPL book as well), spalting lines do not represent the color of the fungi. The fungi might be white or gray or whatever, but the black spalting is not the fungus itself, but a barrier that is erected to block their "turf" from intrusion by competing fungi.

I did some investigation a few years ago about the use of ethanol by the lumber industry to increase yield and reduce kiln time by allowing higher final drying MC. In the early twentieth century, various different processes were investigated and in the patent searches that I did, I found that several of them used ethanol as part of the process. I believe that heat was also used in most of the processes as well. The gist of those methods is basically that ethanol helps soften the lignin and as a result helps in relieving internal stresses that are a cause of drying defects such as warping and splitting. Another thing that showed up in my search was the use of PEG to stabilize wood for specialized applications such as gun stocks and other things where warping would be serious problem. As far as I could find, none of the methods proved economically viable for anything other than specialty products. One thing worth noting is that none of the patent claims mentioned anything about speeding up drying -- only stabilizing the wood.

I had lunch with Dave Smith a few years ago at SWAT and talked to him about what I had found and my opinion that lengthy soaking in ethanol might have more to do with relieving stresses than drying the wood. I gathered that he found it interesting, but not convinced. I can't really argue the point since I have no expertise in the field. I do however observe what happens to my hands when using ethanol for things like dying wood. Even limited contact with ethanol severely drys my hands and causes fingertip cracking. A couple turners who I know have tried alcohol soaking and it seems to me that they do so for a time too brief to do any significant penetration, but I am sure that it is useful for removing moisture down to a few thousandths of an inch which should be sufficient for gluing or finishing oily or slightly wet wood.

I have read threads on forums discussing the question of whether alcohol evaporates from soaked wood leaving the existing water behind or if they evaporate together. I suspect that things are not so simple and at least some of the water has to evaporate along with the alcohol because of the intermolecular hydrogen bond between water and ethanol. My observation is that when I have ethanol in an open container, I have never observed the alcohol evaporating and leaving water behind. The same is true when I have a bunch of rags and paper towels soaked in a water alcohol mixture. They dry quickly and I have not noticed any of them only being wet with water. I don't intend to convince anybody else to change their mind on this matter because for the most part it would be as productive as arguing politics and my thoughts are nothing more than a general observation.

 

[MichaelMouse]

Spalt is like Alzheimer's, a diagnosis by autopsy; mildew and some others more like psoriasis, obvious and annoying, but not life-threatening. Back when I was bagging because "cherry was prone to cracking", I mistakenly boxed up a couple of sweet birch roughs. The hairy white stuff took hold within three days, almost filling the box with hyphae. The surface showed a green crust, with almost no penetration, and no real harm, as far as I could see.

It was anchorseal that introduced me to black mildew. I bought a gallon, slathered it on the endgrain of some roughs, and put them in my quiet corner of the basement, where they promptly grew nasty black fungus. Apparently the surfactant and alcohol antifreeze they put in the emulsion was not antifungal. The black stuff will even grow on cherry, a wood which resists the white bushy type, and discolors to some depth, costing diameter on vulnerable woods like maple.

I've tried pretty near every drying fad that has arisen and faded away for the last 30 some years, and with one exception, had great success in preserving the roughs. Like most people I thought success was because of what I did. Now I realize that it was in spite of what I did. It's like pouring concrete, you can do things that will ensure failure, but you can't ensure success.

Bill, you probably sample the result of the laws of partial pressure periodically without thinking of them. If ethanol did not evaporate without taking excess water with it, distillation would be impossible. So when you pour that B&B to ease your sore throat and sore shoulders after shoveling this weekend, enjoy and understand.

 

[Gary Chapman]

Micheal,
So how do you dry your roughs? I have always used anchorseal and bags. Is tyhere a better way? I use a ton of the stuff and it seems to work for me, am I lucky? Gary

 

[MichaelMouse]

I have a basement and a garage. Summer turnings are set on the basement floor for a week (or so) and then moved to shelves where the air flow is minimal. Winter turnings are put out in the attached, but only passively heated garage, where they stay until I remember to bring them in.

If you are using anchorseal on outside endgrain in a dry place <60% RH, should be able to win the battle between moisture and mildew. If you're putting them in places at >65%, you might start picking up some growth. Once again, success in spite of what we do, not because.

 

[Gary Chapman]

Micheal,
I don't understand the center core in your bowls. I cut out the center core when hollowing if have to use the live center for stabilizing. Am I doing something wrong?

 

[Mark Mandell]

Gary,

Michael uses an older technique of mounting on what's known as a pin chuck, rather than using faceplates and /or scroll chucks during roughing-out bowl forms. The post you see in his pix is where the pin is inserted into the blank and remounted when dry.

Just a different style of mounting; you're not doing anything wrong.

 

[Bill Boehme]

I didn't proofread my post well enough and wrote "intermolecular hydrogen bond" where I meant " intramolecular hydrogen bond" which is different, but how significant, I don't know. Since mixing ethanol and water is exothermic, I presume that separating them is the opposite. Whether this has anything to do with how ethanol and water evaporate, I don't know.

Anyway, except under high pressure and elevated termerature, I am a bit skeptical how much alcohol actually penetrates into hardwood. I think that any perceived benefit from alcohol soaking has a lot more to do with softening lignin to help relieve some stresses than anything else. It seems to me that if alcohol really did a lot to speed up drying and nothing else, it would also probably speed up and possibly exacerbate cracking if we go with the assumption that the reason for drying wood slowly is to minimize cracking.

 

[hockenbery]

Micheal,
I don't understand the center core in your bowls. I cut out the center core when hollowing if have to use the live center for stabilizing. Am I doing something wrong?

Gary,
Most people do bowls as you describe
Turn the outside mount it in a chuck then take out the inside either with a gouge or a coring tool.

The center post method is useful if you have to turn a bowl totally between centers.
When done you can hit the center post and break it off sand the bottom and the bowl is done.

I did a couple of bowls this way 20 years ago. Haven't seen any reason to do one that way since

It takes a lot longer to leave the center post and it doesn't work at all if you want to core the bowl.
That said if someone learns that method and likes it, fine because it will work.

I would not recommend the center post method because it is harder to do and takes longer and in most cases will produce poorer results because you can't follow the curve through to the bottom center when hollowing. Most folks have difficulty visualizing the curve through the post.

It takes about 8 minutes for me to teach someone how to reverse chuck a bowl and true a tenon in a way that centers the rim high and low spots

Have fun,
Al

 

[MichaelMouse]

Anyway, except under high pressure and elevated termerature, I am a bit skeptical how much alcohol actually penetrates into hardwood. I think that any perceived benefit from alcohol soaking has a lot more to do with softening lignin to help relieve some stresses than anything else. It seems to me that if alcohol really did a lot to speed up drying and nothing else, it would also probably speed up and possibly exacerbate cracking if we go with the assumption that the reason for drying wood slowly is to minimize cracking.

From my experiments, using dyed alcohol, not a lot. 48 hours got me maybe 1/8" in maple endgrain.

Rest assured, EtOH isn't going to harm lignin. Lignin does flow, as you know, when wood is steamed or boiled. Applying heat early in the kiln process is standard, though our locals go beyond and steam to make the local beech behave better. You can bet if alcohol did anything positive it would be there, because it's easily recovered.

Alcohols, anything with at least one -OH group, are all more or less miscible in water, and those with higher boiling points can bulk the structure of the wood and lag behind evaporating water, preventing the start of checks. Ethylene glycol, a double, and glycerol, a triol, are the ones that are most often employed. They are effective based on the same physical chemistry laws that the "drying" folks claim to violate in their process.

 

[MichaelMouse]

Micheal,
I don't understand the center core in your bowls. I cut out the center core when hollowing if have to use the live center for stabilizing. Am I doing something wrong?

As indicated, I use a pin chuck for roughing and remounting after curing. If I were coring I'd do the same with pin jaws if I was looking to get round work. Benefit of the pin chuck, aside from greater safety than the spur center spinners get, is that the wood contracts as it dries, allowing me to rebore the hole - precisely centered - after the wood has cured. The pin chuck also allows me to cantilever the piece and make a mortise - which I enlarge to optimum hold once again after drying - my preferred mounting method.

Nothing difficult working around a pillar which gives greater safety between and superior centering. Been done for centuries. http://www.robin-wood.co.uk/index.htm You just have to think your way through.

I don't use hook tools, because I don't know smithing, so I do a regular plunge and roll.
http://s108.beta.photobucket.com/user/MichaelMouse/media/HollowOne001.mp4.html

http://s108.beta.photobucket.com/user/MichaelMouse/media/HollowTwo001.mp4.html

When things are at their lightest, the center is removed and the final passes taken with a broad sweep gouge.

http://s108.beta.photobucket.com/user/MichaelMouse/media/CherryPeelIn.mp4.html

I do the button center outward after reducing to near proper so I don't twist and leave a divot.

Works real well, even for one-run warp-and-go stuff, too. Though for really shallow work, pin jaws are the option of choice.

http://i35.photobucket.com/albums/d160/GoodOnesGone/Bark-up.jpg

I don't reverse to "finish" a bottom, the bottom is finished before I reverse.

 

[Bill Boehme]

I am pleased to see that the hook tool pictured looks exactly like the way that I was taught to make them. I have seen so many variations of hook tools that I had doubts about the "right" way. However, some permutations look as though they might be difficult to sharpen or scary to use.

Until getting the hang of using hook tools, they are both humbling and unnerving. The upside is that the concept of proper tool control (as well as improper tool control) becomes well established in one's mind.

I suppose that a hook tool could be used on face grain turning provided that the overhang is small, but I was taught that the only "proper" use of the tool was on green end grain -- implying small hollowforms with maximum overhangs of about 6 - 8 inches. I am sure that this belief has its roots in the severity of catches that can be produced. Even with green end-grain , I was able to produce some spectacular tool-bending dismounts.

 

[Bill Boehme]

... I don't reverse to "finish" a bottom, the bottom is finished before I reverse.

A bowl has two "bottoms" -- one on the outside and the other on the inside. It appears to me that you and Al are on opposite sides of the bowl.

Personally, I call the outside "bottom" the "foot" and I avoid talking about the inside "bottom" because I invariably wind up confusing other people.

I get Al's point about most new turners having difficulty projecting a curve into a smooth transition through the "bottom" (there I go after saying that I wouldn't) when there is a physical obstruction blocking the view of the other half of the curve. I struggled with that problem for the longest where my goal was to have a "nice" curve without any flat areas or inflections.

 

[MichaelMouse]

I get Al's point about most new turners having difficulty projecting a curve into a smooth transition through the "bottom" (there I go after saying that I wouldn't) when there is a physical obstruction blocking the view of the other half of the curve. I struggled with that problem for the longest where my goal was to have a "nice" curve without any flat areas or inflections.

One of the reasons I don't do tenons on a bowl is my inability to see or make a fair curve to give visual lift without looking like I stood the piece on something. I ended up with "cheeks" on the bowl, like a fat guy's butt bulging over a stool. No such problem when the entire form is visible and palpable.

If you're talking about a fair curve inside, it's probably less of a problem for me than those who step cut. You can see the gouge arcing into and through the wood when hogging, with all but the last inch visible and available to my digital calipers. Then there is the final peel with broad sweep gouges. Avoids many of the problems proponents of "bowl" gouge techniques complain of, because it can't catch, provides a broad reference along the direction of travel to avoid ridging, does not dig the heel to compress and harden, and, most important, keeps me off the coarse end of my sandpaper shelf.

 

[Chip Sutherland]

I leave a center core, too.

When I am turning green wood, I use a scroll chuck but when I reverse it to core it out, I leave a center core just so I can use it as a guide to remount the blank for re-turning. I use the scroll chuck hole for the live center point to more safely secure the blank which is usually out-of-balance or oval blank. I remove the center core when the blank is back round. This process works for me. I use DNA, too, and use Anchorseal and brown paper wrap for my blanks after they come out of the DNA bath.