Freezing to separate water from alcohol for drying green??

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Forum topic by Abter posted 07-25-2017 03:33 PM 1882 views 0 times favorited 9 replies Add to Favorites Watch
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79 posts in 1399 days

07-25-2017 03:33 PM

Topic tags/keywords: question green wood drying turning

Numerous posts here say that soaking bowl blanks in denature alcohol is a successful way to dry green wood fairly quickly. General idea when immersed in alcohol for a few hours the water in the blanks is displaced by the alcohol. You then let the alcohol evaporate for a few weeks, leaving a significantly drier blank.

The downside of this alcohol soak method is the cost. HD sells denatured alcohol is ~$16. Totally submerging numerous bowl blanks in alcohol can require a lot of alcohol.

The cost problem gets worse because the alcohol in the bath absorbs the water (thats the point after all) from the wood, so after using it for a few uses the alcohol “wears out” from having too much water in it. It also ends up with other stuff (sorry for the technical terms here) from the wood, so you gradually get worn out and smelly old alcohol.

Has anyone tried cleaning the alcohol to get the water back out of it? I am not interested in distilling the old alcohol, although I am sure some of you are quite familiar with that process ;)

But another very low tech chem 101 way of de-watering alcohol is by putting it in a freezer. Ethanol (denatured alcohol is 90% + ethanol) freezes at about -170 degrees F. Putting the used mix in your freezer (about 0 F), the water will freeze and rise to the top. You can skim it off and throw it away (errr…dispose of it environmentally properly and safely), leaving “drier” alcohol. A few rounds of this will greatly lower the moisture content.

1) Has any one tried this? Any success? Failure?
2) where does the other wood “stuff” end up. I suspect some will be in the frozen stuff, and others remain in the liquid. The issue is how much in each? If you do this, especially a few times, do you end up with an ever nasty mix of alcohol and resin, sap, bug juice, and a bunch of other organic weirdies ?

-- "Many men fish all their lives without ever realizing that it is not the fish they are after." {often mis-quoted as by H.D. Thoreau}

9 replies so far

View Kelly's profile


3006 posts in 3716 days

#1 posted 07-25-2017 04:08 PM

Makes sense. I froze a batch of fresh squeezed cherry juice. Months down the road, I pulled the jug from the freezer and it was all frozen, except for a little over an inch cylinder down the center. That would be the high concentrate, which had an out of this world, wonderful taste. High sugar.

View ClammyBallz's profile


449 posts in 1908 days

#2 posted 07-25-2017 04:37 PM

You need a cheaper source for alcohol. I just picked up another 5 gallon jug while using a 25% off coupon. $42.20 shipped to my door.

View AlaskaGuy's profile


5797 posts in 3081 days

#3 posted 07-25-2017 04:50 PM

Google is your friend. No I have not tired any of these personally

-- Alaskan's for Global warming!

View Woodknack's profile (online now)


13386 posts in 3152 days

#4 posted 07-26-2017 09:13 PM

The advantage of alcohol is there is almost zero labor. So instead of adding labor to recover alcohol why not just use a slightly more labor intensive method instead, like boiling or a kiln.

-- Rick M,

View TravisH's profile


717 posts in 2707 days

#5 posted 07-26-2017 09:40 PM

Distillation is not feasible for most individuals. I do my fair share at work but don’t see it as feasible for most guys to do at their house. You also get into another fun area frowned upon by law enforcement.

Freezing… You will need to get water content up over 70% by weight to get freezing. I routinely use ethanol/water mixtures at temperatures below zero with no issues at work for crystallization work. Most guys experiences freezing alcohol products is with beer and wine products and in both cases we are talking about a lot of water. I know we kept a freezer full of MD 20/20 g at the house in college and you could “freeze concentrate” that crap and pour that horrible junk out for consumption on occasions as usually the freezer never stayed closed long enough to get that cold.

Molecular sieves and various desiccants are frequently used to dry organic solvents but once again not really feasible for most.

I think the effort and materials needed plus ones times are more costly and just would buy the denatured alcohol.

View Paul Mayer's profile

Paul Mayer

1124 posts in 3837 days

#6 posted 07-26-2017 11:01 PM

I just bought a 5 gallon bucket for $33 at Menards. Special order; took about 2 weeks to get. I soaked 8 bowls, roughly 20” apiece.

-- Paul Mayer,

View AlaskaGuy's profile


5797 posts in 3081 days

#7 posted 07-26-2017 11:36 PM

Distillation is not feasible for most individuals.

- TravisH

I doubt the moonshiners would agree :)

-- Alaskan's for Global warming!

View Abter's profile


79 posts in 1399 days

#8 posted 07-27-2017 02:11 PM

Thanks everybody! TravisH’s comment about needing a high % water to freeze ethanol/water blends was something I didn’t know (I will blame my Chem 101 level knowledge). AlaskaGuy’s link to wikihow was bang on. “Start with a liquid that is 5%-15% alcohol” (freezing method is also called “Mongolian Still). Thinking about it, of course it won’t work for low water contents. It if it did the vodka …~80 proof = 40% alcohol… that lives in my freezer (best martini ever…no ice needed) would have separated long ago.

All demonstrating once again …you can get darn near ANYTHING answered at LumberJocks :)

-- "Many men fish all their lives without ever realizing that it is not the fish they are after." {often mis-quoted as by H.D. Thoreau}

View lew's profile


13114 posts in 4527 days

#9 posted 08-09-2017 04:29 PM

I’m going to try this method-

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

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