# Freeze to Dry



## ghost5 (Aug 19, 2012)

I've never heard of this before today so have no idea if it works or not but I guess it won't hurt to try.

Take a blank, for me 2"x2"x12" and freeze for two weeks then place in fridge for two weeks then it will be ready to turn. The reasoning sounds about right, sort of, but just wondered if anyone else has heard this one.


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## Travico (Dec 25, 2012)

To me, if the blank is full of moisture, then if it freezes, it will tend to crack the blank. Water expands when it is frozen.


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## Dave Paine (May 30, 2012)

+1 with Travico.

Freezing a piece of wood does not mean freeze drying. 

A freezer may have a low relative humidity, but most of the water will remain in the cells as the wood freezes. I have not personally tried this, but I would expect to see cracks.

My recent log section purchase of mulberry had over 25% moisture content. I think if I had put a piece in the freezer, it would have not been good for the wood or freezer.


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## BigJoe16 (Feb 20, 2012)

I would not expect this to work. Just think about a piece of beef. If you take a fresh cut of meat, and put it in the fridge, a lot of juices with seep out onto the plate. But if you took that piece and put it in the freezer, no juices will come out, they will all be frozen in the meat. 


If this worked, you could cut all your firewood in the winter, let it dry for 2 weeks in the yard, then bring it into the garage to thaw for 2 weeks, and it would be ready to burn.


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## HandMadeInWood (Jul 30, 2013)

.


You missed out on one vital process required in Freeze-Drying.

After freezing the sample at atmospheric conditions, you need to subject it to a high vacuum.

The process of Freeze Drying involves the removal of moisture by sublimation. It's a process whereby the frozen water turns to vapour at low pressures without entering the liquid phase.

It won't split. The cellular structure of wood, plus the inherent oils and sap naturally inhibits freeze-stress (splitting), otherwise forests all over the place would disintegrate every winter.


. 


.


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## RusDemka (Jun 9, 2012)

This is interesting...


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## reynoldston (Sep 13, 2013)

Never worked with wood that has been frozen, but I heat my house with fire wood. I keep my fire wood outside and now that you are saying something about I have found when the weather gets very cold the wood is much dryer so I can see where you are right on this.


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## Hwood (Oct 21, 2011)

I have read others pulling wood out the freezer and its sucked dry. Not sure for how long it was in the freezer though. I would be shocked if this was a 2 or 3 week thing though, sure ice will evaporate but its not like ones ice cubes disappear every month in the freezer. Dark cool place of the fridge sounds like mold growth to me.
I heat with wood also, I figured the colder temps ment less moisture in the air and I assumed that's what made for the hotter burns, just a thought.


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## ghost5 (Aug 19, 2012)

Thanks guys. First I never said freeze dried I said freezing to dry and I said I have never tried it nor knew if it worked so saying I missed something doesn't apply. In fact I do know how freeze drying is done having worked around that equipment for many years. 

The idea behind it was the wood cells open releasing moisture then I guess the two weeks in the fridge allows it to leach out whatever is left. That is all I was told and have no idea if it works that is why I was asking not stating fact. 

Personally my two kilns will do a good job or I can microwave it if needed just wondered if anyone had ever heard of it.


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## Cicolid (Apr 10, 2010)

Some of you guys say the wood will split when frozen.

Many countries in Europe etc experience freezing temps' for long periods of weeks or even months at a time.

How come I have never seen or heard of a tree splitting through freezing.

Puzzled.

Col


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## PhilipCollier (Jan 2, 2012)

When I lived in Oklahoma years ago we would have winters getting to -5 or lower. It was common to see smaller trees split and fall. Not from sleet or snow, just the cold.


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## BigJoe16 (Feb 20, 2012)

BlackbuttWA said:


> Some of you guys say the wood will split when frozen. Many countries in Europe etc experience freezing temps' for long periods of weeks or even months at a time. How come I have never seen or heard of a tree splitting through freezing. Puzzled. Col


Trees really to split from the cold. Up in the arctic where it's gets super cold, trees are said to crack and split so bad, they basically explode. 

The colder temps do bring dry air, but it dosent suck the water out of the wood, the ice will crystallize in the wood and be stuck in the fibers. 

The structure of a tree, is basically a big stack of straws. The "straws" run the length of the tree. The water will freeze and get stuck in the straws. 

This is why, atleast in my experience, when drying wood, it cracks less when turned on it's side so the end grain is facing the walls not the ceiling.


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## WeekendTurner (May 27, 2011)

Travico said:


> To me, if the blank is full of moisture, then if it freezes, it will tend to crack the blank. Water expands when it is frozen.


Water shrinks when frozen, otherwise ice cube trays would overflow. Still likely to crack, but for the opposite reason.

...


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## DST (Jan 10, 2011)

WeekendTurner said:


> Water shrinks when frozen, otherwise ice cube trays would overflow. Still likely to crack, but for the opposite reason. ...


Time to review some basic physics


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## DST (Jan 10, 2011)

Hwood said:


> I have read others pulling wood out the freezer and its sucked dry. Not sure for how long it was in the freezer though. I would be shocked if this was a 2 or 3 week thing though, sure ice will evaporate but its not like ones ice cubes disappear every month in the freezer. Dark cool place of the fridge sounds like mold growth to me. I heat with wood also, I figured the colder temps ment less moisture in the air and I assumed that's what made for the hotter burns, just a thought.



Actually if you leave a nice cube in the freezer long enough it will shrink down . Sublimation


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## WeekendTurner (May 27, 2011)

DST said:


> Time to review some basic physics


Yes, and to stop posting after a double scotch. I was thinking -- well, if you can call it that -- of sublimation.

...


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## Longknife (Oct 25, 2010)

WeekendTurner said:


> Water shrinks when frozen, otherwise ice cube trays would overflow. Still likely to crack, but for the opposite reason.
> 
> ...


Nope, water expands when frozen. Try to freeze a bottle of water and you'll see what happens. Or leave water in the pipes in an unheated house during the winter....

If the theory of drying wood in the freezer was correct I could just leave milled lumber out in the winter and have it dry in two weeks. I can tell you that won't happen. On the other hand it's possible to air dry lumber in the winter, it just take longer time. The risk of cracking isn't larger than normally, mostly depending on the fact that wood harvested in the winter have a much lower moisture content than during the summer.
Frost cracking does happen to standing trees sometimes. If you go out in a forest on a clear winter night with temps of -25F you are likely to hear very loud cracks, like gun shots. That's from trees cracking.


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