Alcohol Question.

[Steve Worcester]

If I remember correctly, the summation that the alcohol was not penetrating deeply was based on one persons observations of the depth of staining by immersion in their (now diluted) alcohol bath.

In the paper you sight (and a good link I might add) , which I did skim, it talks of the alcohol/ether bath (the closest to what we are talking about)

"This means that when the ether evaporates, the surface tension forces are so low that there is no appreciable collapse of the weakened cell wall."

In their case, they use ether which evaporates extremely fast and they use successively stronger solutions, and build up to a level where (after alcohol and then acetone) the ether is holding up the cellular wall and the tension in the wall is low. While impractical in most woodturning situations, because of toxicity, it does lend some credence to the alcohol theories.
Remember that they are talking about preserving wooden artifacts. In their case (TAMU) it is wood that most likely has already been dried and through environmental conditions (shipwrecks, terra burials) now needs to come back to an equilibrium moisture content with minimal damage. (granted all of my verbiage is purely based on hearsay)(no, really).

And, for what it is worth, I do learn so much from these spirited conversations, now if I could only increase my retention....

 

[Mark Mandell]

Smoked?

You forgot smoked.

Dave, Mah Main Man,

You using EZ-widers or jus plain ol' copy paper? 😀 😀

 

[Ken Grunke]

Back to removing water from used alcohol...

How about freezing?
More than once, I've forgotten about a bottle of beer in the deep freeze, which was only supposed to be there about an hour 🙁
The water freezes before the alcohol, making it easy to seperate.
I'll try putting my well-used DNA in a milk jug (not full, of course) and see what happens.

 

[William Young]

Ken;
Sounds like you may have hit on something that I have not seen mentioned before about the water content in alcohol. Would that ever be a neat way to find out especcially if the water were to separate from the alcohol and could be removed as ice. ..
Keep us posted on your experiment.
W.Y.

 

[Ken Grunke]

Caution is called for!

We should all know that skin contact with DNA is not safe, but the thought that if it were below freezing temperature could be even more harmful, in an immediate way, didn't occur to me until a few hours after my post in this thread. I once heard a story of someone chilling a bottle of liquor in the deep freeze, then drinking straight from the bottle with dire results. I don't know what a small splash of sub-32 deg. F. alcohol will do to skin, and would rather not find out--so I just wanted to put a heads up on this possibly hair-brained idea of mine, and hope that no one does any harm to themselves.
I just decanted a half-gallon detergent jug of DNA back into it's original tupperware container with sealed lid after it was in the deep-freeze for about 5 hours, and saw no sign of frozen water. Could be it wasn't in long enough, or simply had little water to begin with.
I hope that those who contributed earlier in this thread, with more than a basic knowledge of chemistry, can add their input here.

 

[Brian Hahn]

Removing water from DNA

First a word of caution: the government has rules about concentrating ethanol by either freezing or boiling. It's a regulated business and they want their money.

I dusted off a few old text books and reference books. As I expected, I couldn't find any phase diagrams for freezing an ethanol-water mixture. My trusty CRC (Handbook of Chemistry and Physics published by CRC) had bits and pieces of information.

Freezing: Pure ethanol freezes at -177.3 C. The table of ethanol-water mixtures only gave the freezing points from 0 - 32% ethanol, and the freezing point for the 32% ethanol mixture was -22 C. Not really encouraging for home separation of stronger ethanol mixtures.

Boiling: Distillation is the "standard" method for purifying ethanol, used in industry, the lab and by those good ol' back woods boys. As mentioned earlier, the ATF has a very strong interest in this type of activity. But just for grins, here's some information. Assuming a decent distillation apparatus with a reasonable number of theoretical plates in the column, the methanol (denaturant in DNA) will come off first at 64.5 C. Immediately after that, and probably mixed in with it, is the water-ethanol azeotrope (95% ethanol, 5% water) at 78.2 C. This will tail off to pure water at the end.

One nice side effect of either method is that it will significantly reduce (freezing method) or eliminate (boiling method) the impurities in the solution. 😀

Please note that all those temperatures are degrees C.

-Brian
Slowly posting my way to being a full member...

 

[Ken Grunke]

Thanks for the reply, Brian--nice to hear from a fellow Wisconsinite.
Now you have me all worried about the Bureau of Alcohol, Tobacco & Firearms busting in my door for having a gallon of brown DNA in my deepfreeze 😱
All kidding aside, thanks for those temp figures. Your reply made me think harder about my original question. After re-reading all the previous posts (especially Dave Smith's) and finding out that water and alcohol are miscible (new term for me, but well defined by Dave) I'm satisfied to know that a small percentage of water in alcohol would not seperate and turn to ice. And that's a good thing, otherwise we'd find chunks of ice in our vehicle's cooling system 😀 Us Northerners can appreciate that!
William, sorry to get your hopes up, and thanks for starting this very interesting thread 🙂

 

[William Young]

Thanks Ken;
Yes it has been very interesting. All the technical stuff doesn't mean much to me so I tend to just scan over that part but I am sure it means a lot to those that are scientifically inclined. My original question was about discoloration of the alcohol and that brought forth some intersting discussions including the one you suggested about freezing. But I was going to let you try that one first 😀
The part that is most interesting to me is how well it has worked since I started using it.
There are some that claim the method is scientifically incorrect but perhaps they have not actually tried it. I don't hear many that have tried it saying that they tried it and it didn't work though .

Just yesterday I final turned a 11.5" birch bowl. It was one of four thatI turned green out of the log on June 16th and they are all dry now and not the tiniest trace of a crack anywhere.

Thanks for all the responses re coloring , dilution, etc.
I think I will just go ahead and not worry too much about the amount of water in it because it seems that adding more alcohol as the solution evaporates and/or soaks into the wood will be enough to recover it to the sufficient strength to do the job .
If it ever gets to the point that I feel it is not working as well as it should due to water dilution, I will just dispose of it and start over again. At least it will have well payed for itself by then in both time and in the saving of some nice pieces of wood from cracking while drying.
W.Y.

 

[Dave Smith]

Brian, thanks for the explanation as to why freezing to separate water and alcohol is not going to work in the home freezer. I knew it would not work but didn't have the time to research the particulars such as temperature. I have avoided referring to the water-ethanol azeotrope (95% ethanol, 5% water) in all my writing about the alcohol drying process.

On an other note, I found out Friday that I need a permit from the ATF to purchase SDA(Specially Denatured Alcohol) from a distributor. The SDA I wanted to purchase in a 5 gallon container has only methanol as the denaturant. They would sell me industrial denatured alcohol in 55 gallon drums with no problem. This stuff has a couple of denaturants that don't sound to good to me like MIBK. I went to the ATF web site and found out I am suppose to register with a letter if I have more than 5 gallons of industrial alcohol on site.

A note on stills. If you do any thing to increase the ethanol alcohol content of a solution your still is suppose to be registered with the ATF.

Dave Smith

Master wood pickler in Longview, WA.

 

[MichaelMouse]

If I remember correctly, the summation that the alcohol was not penetrating deeply was based on one persons observations of the depth of staining by immersion in their (now diluted) alcohol bath.

In the paper you sight (and a good link I might add) , which I did skim, it talks of the alcohol/ether bath (the closest to what we are talking about)

"This means that when the ether evaporates, the surface tension forces are so low that there is no appreciable collapse of the weakened cell wall."

In their case, they use ether which evaporates extremely fast and they use successively stronger solutions, and build up to a level where (after alcohol and then acetone) the ether is holding up the cellular wall and the tension in the wall is low. While impractical in most woodturning situations, because of toxicity, it does lend some credence to the alcohol theories.

The acetone or ether is used to replace the ethanol in a process involving the same dilution method. None of which adds a bit of credence to the alcohol soak method as presented. The soak times are simply too long, and replacement of dilute solutions is required. Not to mention that, if the second and third steps are unnecessary because alcohol alone will suffice, why go to the time and expense of doing them?

There are two things which you want to remember about wood structure and nature that pertain here, neither of which is clearly presented by the "holding up the cell wall" phrase. First, unbound water is contained within the boundaries of the cell walls. Second, bound water is influence-bonded to the sugars in the cellulose itself. It is the loss of this water which concerns us in the case of non-waterlogged wood. With waterlogged wood, as stated in the piece, lignin has been lost - the glue that binds the vascular structure together. With little lignin to bind the cell structures to one another , the structures might collapse into the cytoplasmic lumen. This as opposed to thinning of the cell walls due to loss of bound water allowing closer packing of cellulose itself.

 

[dkulze]

Michael,

What causes wood to swell when exposed to water but not when exposed to alcohol?

Dietrich

 

[TEK]

cell membrane

Here is a question for all of you, especially the organic chemists. I remember from high school, I won't say how many years ago, alcohol dissolves part of the lipid layer in the cell membrane, as will many other organic solvents. The cell membrane is basically a lipid layer between two protein layers. The point is, when the lipid layer is dissolved, the size of molecules that can pass through the membrane increases. The teacher said this was part of the problem of hangovers from becoming intoxicated. Molecules that don't normally pass through the cell walls do, so you lose some stuff from cells that should stay in, and get some stuff in that should stay out. Dehydration is another cause of hangovers. Dehydration caused by alcohol. Wood has cell walls, but still has a cell membrane inside them. If the alcohol changes that membrane, does it change the rate of flow across that membrane? I would think so! Anyone have views on how this would affect the drying rate?

 

[MichaelMouse]

Here is a question for all of you, especially the organic chemists. I remember from high school, I won't say how many years ago, alcohol dissolves part of the lipid layer in the cell membrane, as will many other organic solvents. The cell membrane is basically a lipid layer between two protein layers. The point is, when the lipid layer is dissolved, the size of molecules that can pass through the membrane increases. The teacher said this was part of the problem of hangovers from becoming intoxicated. Molecules that don't normally pass through the cell walls do, so you lose some stuff from cells that should stay in, and get some stuff in that should stay out. Dehydration is another cause of hangovers. Dehydration caused by alcohol. Wood has cell walls, but still has a cell membrane inside them. If the alcohol changes that membrane, does it change the rate of flow across that membrane? I would think so! Anyone have views on how this would affect the drying rate?

You're mixing a lot of unrelated information to come to some strange conclusions. Alcohol is used to dehydrate cells in Histology, while preserving their structure, not to destroy the lipid bilayer. For that, detergents are used.

Wood is dead. A diagram from the FPL (copyrighted, quoted for review of an excellent article) site is included for your reference on how cellulose and hemicellulose cell walls are structured. The pipe-like structure of a typical hardwood is actually visible to the naked eye. Semipermeable membranes and salts don't play here. There is no cytoplasm to support the membrane.

Dehydration in humans is a result of the diuretic effect of alcohol and its breakdown products on the kidneys. It makes you urinate. Water goes with, and is reclaimed from the cells through blood and lymph. Of course coffee or tea are also diuretics. Or that favorite blood pressure/CHF medicine furosemide. Only thing the two have in common is the word dehydration.

 

[MichaelMouse]

Michael,

What causes wood to swell when exposed to water but not when exposed to alcohol?
Dietrich

Swells when I use shellac at my house. Not as much as if I soaked it in water, though. I have to knock down the fuzz popped up from sanding after the seal coat.

I rather suppose that if the wood were at or above the FSP, it would not swell, because the cause of wood swelling and contracting with changes in RH is the bonding of water to suitable sites on the sugars which compose cellulose. At 10% moisture content, books say 2/3 of available sites are available, since the FSP is ~30%. Process is the same as the one that causes the sugar in your sugar bowl to harden in damp weather.

I have never tried shellac mixed with absolute alcohol - no water at all. Wonder if it would be different than 5% water.

 

[MichaelMouse]

Freezing: Pure ethanol freezes at -177.3 C. The table of ethanol-water mixtures only gave the freezing points from 0 - 32% ethanol, and the freezing point for the 32% ethanol mixture was -22 C. Not really encouraging for home separation of stronger ethanol mixtures.

One nice side effect of either method is that it will significantly reduce (freezing method) or eliminate (boiling method) the impurities in the solution. 😀

Hmmm, maybe in southern Wisconsin they don't make apple jack by freezing the water out, but up north :cool2:.

It'll reduce them if they don't depress the freezing point too much, and you decant when solubility's down.

 

[Caniac]

Dehydration in humans is a result of the diuretic effect of alcohol and its breakdown products on the kidneys. It makes you urinate. Water goes with, and is reclaimed from the cells through blood and lymph. Of course coffee or tea are also diuretics. Or that favorite blood pressure/CHF medicine furosemide. Only thing the two have in common is the word dehydration.

Alcohol and caffeine work similarly in that they inhibit the release of ADH (antidiuretic hormone), which thereby limits the reclamation of water in the collecting duct in the kidney-the ultimate source of concentration (or lack thereof) of urine. Furosemide (lasix) is a "loop diuretic" and has a very different mechanism of action- none of this has anything to do with wood, of course. But the kidney is way cool.

 

[Brian Hahn]

Hmmm, maybe in southern Wisconsin they don't make apple jack by freezing the water out, but up north :cool2:.

Yup, freezing works great at low alcohol levels, especially on those cold winter nights when it's nice to have a little nip to ward of the chill. 😀

But at the other end of the scale where it is 80% or more alcohol, it doesn't work quite as well. Its more water that is dissolved in alcohol. As I said, I couldn't find a phase diagram for the alcohol-water system, but it is entirely possible that the water will act as a freezing point depressant for the alcohol. Now we are talking really chilly.

Too bad I'm retired and 1000 miles from where I used to work. It would be interesting to pop into the lab and run a few experiments. And liquid nitrogen is nice to play with on hot and humid days. 😉

 

[dkulze]

That answered my question, Michael. I'm guessing that you're right. A pure alcohol shellac mixture probably would not swell the wood.

Now, my question would be, does addition of the alcohol to a piece of wood debond the present water from the cellulose or are we just looking at a dilution effect?

And, yes, when the wood is green, water does not swell it.

Finally, I'm familiar with the use of dry wood wedges driven into stone and doused with water so as to swell and crack the stone. I would have assumed some sort of active takeup through a semi-permiable membrane was reponsible for this, as a passive process would not actually increase pressure in the wood, just expand it where no external pressure was present. What would be responsible for this effect?

I'm big into trying to understand/explain observed effects so thanks to all bearing with me on these questions.

Dietrich

 

[MichaelMouse]

Now, my question would be, does addition of the alcohol to a piece of wood debond the present water from the cellulose or are we just looking at a dilution effect?

Finally, I'm familiar with the use of dry wood wedges driven into stone and doused with water so as to swell and crack the stone. I would have assumed some sort of active takeup through a semi-permiable membrane was reponsible for this, as a passive process would not actually increase pressure in the wood, just expand it where no external pressure was present. What would be responsible for this effect?

I'm big into trying to understand/explain observed effects so thanks to all bearing with me on these questions.

Dietrich

That's what life is, gaining confidence we can deal with it through understanding what we see.

Best answer I can give is to refer you to http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Carbohydrates.html or similar to see the structure of cellulose. Then understand that water is a highly polar - charges unequally distributed - molecule that snuggles up readily with the riboses where their shape and charge complements the water molecule. It's actually bonded by Van Der Waals forces to the larger molecule.

When there's very little vapor pressure to help maintain this weak bond, it comes out. That's what dries the wood.

 

[TEK]

Another question.

When there's very little vapor pressure to help maintain this weak bond, it comes out. That's what dries the wood.

Many of us have vacuum pumps for vaccum chucks. Does this indicate that vacuum drying may be an effective alternative? Has anyone experimented with vacuum drying?

 

[Mark Mandell]

Has anyone experimented with vacuum drying?

Tom,

Vacuum drying wood, with and without heat, is not new, but I seem to recall that it's not cost effective. As the vacuum develops, the water content will tend to boil off at lower temperatures (Boyle's Law? 🙄 ), but from what I read it doesn't help with cracking or warping and may even exagerate those problems. You can pretty easily hook up your vacuum pump to a home made vacuum chamber (like a veneering bag) and try it for youself.

I tried the LDD thing :mad:.

I now use alcohol on some pieces. My goal was and is to increase the percentage of uncracked and minimally warped pieces; not to speed up the drying process; I don't much care how long the piece takes to dry. In any given bowl turning session I am likely to turn both wet and dry wood. The wet ones go to the soak and/or the drying rack and the oldest dry roughs come out to be finish-turned. It's a continuing cycle so I always have something to start and one to finish. :cool2:

Mark

 

[MichaelMouse]

Tom,

Vacuum drying wood, with and without heat, is not new, but I seem to recall that it's not cost effective. As the vacuum develops, the water content will tend to boil off at lower temperatures (Boyle's Law? 🙄 ), but from what I read it doesn't help with cracking or warping and may even exagerate those problems. You can pretty easily hook up your vacuum pump to a home made vacuum chamber (like a veneering bag) and try it for youself.

No matter what the pressure, what you really want to control is the relative humidity. A veneering bag is not a good solution, because it'll be really tough to get the resulting moisture out in a timely manner.

The advantage to a vacuum kiln is that it aids moisture loss from the interior, maintaining a more friendly gradient, and it does it without adding too much heat. Makes it possible to run wood of various dimensions and even species in the same batch. It can also do absolutely green wood, something operators of a standard kiln generally avoid. The vacuum and ventilation are controlled by constant reading of relative humidity. As one manufacturer says "true climate control."

Before I found out I didn't have to do anything other than put roughs in proper places, I had a passive "kiln" built with a couple of muffin fans, one for circulation, one for exhaust, and the controller from a dehumidifier. Worked great, though it was sort of a pain having to make a batch and leave it rather than turning as desired. Given subsequent success doing almost nothing, perhaps "failure was not an option."

 

[Mark Mandell]

Gee,

Guess what I read, that the vacuum tended to force water to leave the wood's interior too fast and created stress and warping unless regulated and watched, was "all wet." Have to hunt up that previous informant as tell them to redo his/her information.

M

PS: Tom, please disregard the first half of my response to your question.

 

[MichaelMouse]

Gee,

Guess what I read, that the vacuum tended to force water to leave the wood's interior too fast and created stress and warping unless regulated and watched, was "all wet." Have to hunt up that previous informant as tell them to redo his/her information.

M

Or, you might look up information elsewhere for comparison.

http://www.fpl.fs.fed.us/ with a search on vacuum kilning will turn up a lot of information. Not a lot in support of your position, rather just the opposite. The process has some big startup expense, but is basically deemed worth it because it reduces drying defect significantly in larger sections and woods most susceptable to drying damage. Computer controls have really made a big difference.

The manufacturers of same are also pretty proud of their products, and you can read about that by going to http://www.metacrawler.com/index.html and searching for vacuum kiln.

Happy to do your research for you.

 

[Mark Mandell]

Happy to do your research for you.

Thanks, but that's not necessary.

All the information relating to vacuum kilns from government and trade info organizations and commercial sites that I have reviewed had to do with drying of dimensional timbers using very substantial, expensive, and carefully controlled installations, using both vacuum and significant heating (SSV, RFV, etc.), which are all presently far outside any realistic application by even a production turner, let alone anyone who is likely to post on or even read this Board. Of course drying dimensional lumber that is, perhaps, 1-2% end grain is somewhat different from drying items that are more than 60% end grain in highly figured woods, and may present somewhat different dynamics and problems. But perhaps not. I don't profess to know nor do I feel the need to find out.

It may, however, present you with a significant opportunity. Consider applying your superior knowledge to develop and market a woodturner's vacuum kiln that will do what you maintain it will. With all the turners seeking to get their stuff dry and finished without cracking and warping in the shortest time possible, I would think that the "M. Mouse Turner's Vacuum Drying System" could be a valuable addition to literally many hundreds of woodshops provided it can be brought out at a viable price.

I'd suggest, however, that you pick a name that won't invite the Rath of Disney for trademark infringement. 😀

Mark Mandell

 

[dkulze]

Being the sick and obsessed f#$k that I am, I actually went to sleep thinking about how to make a vaccum kiln last night. Sad.

You can pick up unfilled propane tanks pretty inexpensively (new, not used. used go boom.). Cut in half. Install rubber gasket. Attach vaccum pump to handy fixture on the top.

Good to go for anything up to about 13" diameter and 16" tall (rough guess, didn't measure yet).

For heat, add a layer of pink insulation on the outside and a cheap hotplate set on low.

So, any major holes in this plan?

Dietrich

 

[Mark Mandell]

So, any major holes in this plan?

Research turned up a problem or 2.

Seems as though even brass and steel vacuum pumps do not hold up long when they're used for pumping water which also brings some extractives with it. The vacuum kilns now use stainless pumps, so don't wax your Gast on the little experiment.

While you can heat the tank, plain infared doesn't transmit very well in a vacuum. The kilns use heating blankets or platens with high temp steam that actually contact the wood or RF (radio frequency = microwave?) generators in the sealed box to raise the temperature. You also should have a temperature sensor in the wood; keep it under 212* or you've got problems so the info said.

 

[MichaelMouse]

Being the sick and obsessed f#$k that I am, I actually went to sleep thinking about how to make a vaccum kiln last night. Sad.

You can pick up unfilled propane tanks pretty inexpensively (new, not used. used go boom.). Cut in half. Install rubber gasket. Attach vaccum pump to handy fixture on the top.

Good to go for anything up to about 13" diameter and 16" tall (rough guess, didn't measure yet).

For heat, add a layer of pink insulation on the outside and a cheap hotplate set on low.

So, any major holes in this plan?

Dietrich

Not enough "holes," actually. You have to get what comes out of the wood out of the way, or it will become a static system. It's relative humidity that counts, not vacuum. The vacuum, just as the heat in a conventional kiln, is there to accelerate the natural loss of water by controlling RH.

Second, the use of heat is one of the factors that's carefully controlled in a vacuum kiln, tradeoff is electricity for vacuum versus heat for standard. The lower temperatures favor less degrade from cell collapse - honeycomb - while the vacuum allows the process to be fast.

Read up a bit from either of the two directions I posted above. A couple of the kiln manufacturers have some pretty good information on their machinery, though the key to the process is what makes your jug idea unfeasable - control of relative humidity in real time. My original air kiln was closer to that than your vacuum idea.

If you want to suck the air out of something, try using it to stabilize pen blanks or such. Too easy to air dry everything for we turners, because we deal in small stuff, and other opinions notwithstanding, it's to our advantage to have so much endgrain on a bowl - it dries sooo much faster than face grain.

 

[C Edward Moore]

If you want to suck the air out of something, try using it to stabilize pen blanks or such. Too easy to air dry everything for we turners, because we deal in small stuff, and other opinions notwithstanding, it's to our advantage to have so much endgrain on a bowl - it dries sooo much faster than face grain.

Beauty is in the eye of the beholder. It is the excessive amount of endgrain versus facegrain and the freedom to move in a turned bowl that causes the warping that we wish to avoid. If a vacuum caused the endgrain to lose water even faster, then it is my best guess that warping would be increased by this process.

 

[dkulze]

Ah well. Was worth a thought. Thought I had a lightbulb. Turned out to be phosphorescent slime. Bumma.

Thanks for the thoughtfull shootdown. Quite informative.

Dietrich

 

[Ken Grunke]

Do a Google search in rec.crafts.woodturning for "vacuum drying" and you'll come up with some interesting discussion on the subject.
There was a fellow named Earle Rich who was working seriously on it between around '98 and '01, then it seems he dropped the project.
Also, Fred Holder published an article in the Mar. '98 issue of More Woodturning on a vacuum drying kiln system.

 

[Gretch Flo]

alcohol question

I have used the alcohol drying for the last 6-9 months and have been pleased. I have a moisture meter so can watch it pretty closely and return after moisture is 10 % or so. Usually 1-4 wks (oak took the longest to reach 13%). I turn fairly small bowls (6-14 inches.) . Still got some cracking in oak and crab apple. The "vat" I have has a capacity for 10 1/2" diameter. I kept adding more DNA as my bowls got bigger to submerge. When I had larger bowls/platters recently of Spalted maple fork, I used a heavy trash bag and soaked 1-2 days. It took longer (2 months to reach 16%) to "dry" and stabilize, but the wood was also thicker. It did not kill the lg grubs-my gouge did! I then turned some smaller red box elder in my "vat" which in the past dried quite quickly(1-2 wks). This last batch of 10 inch bowls are taking much longer dry (stablize-4wks+)).
My question is has the DNA become too dilute? Most people are talking about just adding more DNA to bring up volume, not concentration. There was talk about using a antifreeze tester or other, but what concentration would I be looking for. I have used 2 gallons for 20-30 (guess) small to med and a few lg bowls and still have a gallon or more in my "vat". Do I start all over ($4/qt).-expensive 🙁 , or just add to it even through the volume is adaquate.
I sure do like the instant gratification. I discolored it with bk walnut and it didn't affect whitish maple or box elder. Thanks, Gretch

 

[Steve Worcester]

I THINK that any water that would be present in the mix evaporates. But I would like to see a study on that.

Personally, I like the process. I recently had some Aus. Euc burl that is so heavy and wet, I took the plastic wrap off after 8 months and it started cracking within a few days. I turned some square lamp out of it and did the alcohol soak. With that wood, you really have a hard time air drying it. Sure is cracked, but the warping and cracking are part of the charm of the pieces.

 

[MichaelMouse]

My question is has the DNA become too dilute? Most people are talking about just adding more DNA to bring up volume, not concentration.

No worry. Your loss of volume is largely due to alcohol soaking into the wood to occupy some of the space freed up by the loss of water that hit your wall. Gain in specific gravity in the remainder comes from alcohol, with its lower boiling point, evaporating faster than the water it's mixed with.

None of this will affect your pieces, because the unbound water/ETOH still has to evaporate before the bound water finds it possible to break the bonds holding it to the sugar, seek the surface and be carried away in the air. Your increase in dry times is likely caused by the higher relative humidity that comes with springtime. Easily verified by using a humidity gage.

Maple turned three weeks ago and stored in my heated basement is almost dry, where the stuff I turned last week is growing mildew because of the rains and the concomitant higher relative humidity.

 

[Dave Smith]

My question is has the DNA become too dilute? Most people are talking about just adding more DNA to bring up volume, not concentration. There was talk about using a antifreeze tester or other, but what concentration would I be looking for. I have used 2 gallons for 20-30 (guess) small to med and a few lg bowls and still have a gallon or more in my "vat". Do I start all over ($4/qt).-expensive 🙁 , or just add to it even through the volume is adaquate.
Gretch

Hi Grertch,

The soaking solution has a low percentage of alcohol. You can find more information on my Alcohol Soaking Bolg . If you have a scale that reads in grams I have a procedure for calculating alcohol concentration using weight. Let me know if you would like me to send you a copy. I paln to put it on my web site or bolg in my spare time.

I am not sure a moisture meter is the best way to determine when a bowl is dry. That is why I recommend weight to indicate when a bowl has reached equilibrium with the surrounding air.

Dave Smith

Spaded the garden yesterday and moving slow this morning in Longview, WA.

 

[LANKFORD]

Response to this thread is very interesting. More than 3000 viewers and 74 responses. Wow! Is it alcohol regarding wood turning or do the viewers have their mind on other beverages on this Mothers Day?

By the way, Happy Mother's Day to all Mother members.

 

[David Somers]

OK...I am not at all sure I should throw this into the mix of this thread or not. Sometimes it seems to fit, sometimes not. If you folks don't think it should be in here perhaps Steve or Jeff could delete it or move it elsewhere?

Out here in the Hawaiian Islands the turners have been telling me that they have tried all kinds of things to stabilize their woods and had no luck with any of them, DNA included. The folks telling me this are what I think of as "The Big Kahunas" of Hawaiian turning. They are making their living providing the high end galleries and resorts with gobs of stunning bowls and vases and platters and art work from Koa and Mango and other Hawaiian woods.

The issues they were trying to resolve, especially with Koa, were the very long drying time they had to endure after roughing out a form, and the fact that during the drying process they were losing a distressingly high percentage of their work to cracking. They tried DNA in various forms, they tried soap from Costco, they tried all kinds of things and found it all made little difference. They were looking at this from a purely economic standpoint because the issue was affecting their income. Many of these Hawaiian woods are rare and they have to pay to buy a tree. Losing a big roughed out Hawaiian Calabash form made from expensive and hard to get Koa really hurts, especially when you had to let it sit for a year or more waiting for it to dry enough to be completed.

Then someone tried a product called Woodturners Choice from a company called Cedarcide. (www.cedarcide.com) They love it. They rough turn a bowl, brush or spray on the product right away, and in the case of most woods let it sit about 3 days and then finish it. In the case of Koa they found 2 weeks was better. After that they could complete the turning and apply finish and have the whole piece sitting in a gallery in under a month. Their loss rate due to cracking went wayyyyyy down and it also seemed to have the beneficial effect of killing the insects that were their largest pests, like powder post beetles and other critters. It is supposed to be non toxic and doesn't affect the color of the wood or its ability to take the finishes used out here. The folks I talked to about this have said the product made a big difference in their work and income. Stuff runs about $60 a gallon here. One person brings it in by the 50 gallon barrel and repackages it and sells it at cost to other turners.

Now.....a couple of caveats....I am a total newbie turner. Look at my gallery here and you will see the sum total of my turning experience, a whopping 9 bowls. Take anything I say with a big grain of salt. I recently picked up a gallon of this stuff to try, but have been on the road so much all I have been able to do on the lathe is dust it off between trips so I have NO direct experience with this. These folks are into this stuff in a serious way though and have the bottom line in mind in all they do so I tend to believe them when they tell me something is worth while or not. And finally, I have no interests at all in this company.

So.....after all that.....I am curious.......Why would the experiences of turners out here regarding DNA be so different than what I am hearing from so many folks on the mainland through this thread? I would be curious to see a show of hands indicating how many have had good luck with DNA, and how many can't tell the difference? (Jeff and Steve....can the Forum do a survey?) And of course, have any of you folks had experience, good or bad, with this Woodturners Choice stuff?

Again, if you want to see this thrown into a different thread or just deleted as irrelevant please feel free! I won't take offense. I brought this up because this has been a fascinating thread to me, and related to this $60/gallon bucket of wood stabilizer I now have in my shop waiting to try.

Thanks everyone! This has really been a good thread. I don't normally sit down and read each and every posting in a two page thread like this, but I did for this one.

Dave

 

[Dave Smith]

At least one Big Island turner uses the DNA method.

I attended the Big Island woodturners club in January of 2005. Doug Leite hosted me for the day. He sent me this email dated 9/22/2005. Perhaps you can talk to Doug and see if the alcohol method is still working for him. If the photo does not appear check my alcohol soaking blog. I will add Doug's feedback and picture soon.

Dave,
Thank you for bidding on that NIP piece. Seems If I said that I was busy, would you believe me? Well, as they say, 1 pic is worth 1000 words. Attached is a pic of the Hollow forms that I am working on right now.
Top row right with collars are due for final sanding and removing bottoms today. Then finish and ship next week.
Top row left have OD turned, ID and collars next week
Middle row is the next batch. There are others air drying and also in my kiln. There is a whole lot more(30?) in Mango and some (20?) in what may be either Orleans Plum, or Star Apple wood. We are not sure, but it sure is curly.
Bottom row blanks I cut and turned round yesterday, and must shape outside and hollow out next week, then soak in ALKY.
Dave, If not for your ALKY protocol, I would not be able to do all of these, and more, by Thanksgiving.
Bear in mind that I have completed and shipped at least 30-40 already. So, I am taking some time to thank you for sharing this great process with us and conveying the impact it has on me.
As soon as I get a little ahead, in a week or so, so that I can get into my Metal Shop (garage) I will finish a surprise that I believe that you can use.
I loke the pics of your square plates and what you did with the Koa that I gave you. I am cutting a lot of nice wood lately and am saving what I can that would make more plates as those shown. A goody box will be forthcoming in a few weeks.
Aloha, Doug

In the mean time try the alcohol soaking method, you might like it. The next time you get to Tex's have a malasada for me.

Dave Smith

Way past my bed time in Longview, WA.

 

[MichaelMouse]

Out here in the Hawaiian Islands the turners have been telling me that they have tried all kinds of things to stabilize their woods and had no luck with any of them, DNA included.

If the objective is to stabilize, the only method(s) with any validity appear to be "bulking" methods like PEG and silicone like the cedarcide you referenced. What they do is use water to carry a soluble solid into the wood where, once the water has been removed, it remains behind. The acrylics seem to work less by bulking than the glue effect, where it slows the rate of interior loss as it reinforces the lignin bonds at the surface. What can't begin to crack can't continue. Perhaps if the stuff were not so expensive, and people not so impatient, a long soak would tell. In theory, should be the same.

Unlike the above discussion, however, one size does not fit all when something's actually happening. The soak times and concentrations must be fairly carefully monitored for the above, and varied according to the species of wood. When nothing's happening, as with alcohol, the user may disregard concentration, which demonstrates that there's no "replacement" or "displacement" or any chemical reaction involved. They may disregard soak times, even though the rate at which water penetrates wood varies with species and orientation as well.

In doing the balancing act between drying speed and degrade, the most important thing you can do is have a handle on relative humidity. It's loss of water, after all, that causes the wood to distort. Frankly, I'm rather surprised that tropical woods with weak seasonal rings would give a lot of trouble in a humid climate. Knots and figure are, of course, another matter.

 

[John Nicholas]

Hi Grertch,

<SNIP>

I am not sure a moisture meter is the best way to determine when a bowl is dry. That is why I recommend weight to indicate when a bowl has reached equilibrium with the surrounding air.

Dave,

What kind of scale(s) do you recommend and where do you find them? Any ideas?

John 🙂