# Moisture in wood



## bberchin (Nov 25, 2012)

Question for you all with experience here- can wood that was dry pull moisture back in when it's stored in a cold, sometimes damp place even though it never comes in direct contact with moisture? What about climate change- cold to hot- will dry wood be effected enough to expand and contract?


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## Logger (Nov 26, 2009)

If not stored in a heated/ dry area wood will pick moister back up.


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## fromtheforty (Jan 15, 2011)

Absolutely!


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## Brian T. (Dec 19, 2012)

Water in wood is in two places =first, there's the "free water" in the volumes of the wood cells. If you get rid of all that, what's left is the "bound water" which is sort of attached to the chemistry of the wood cell walls. The bound water is a big part of steam bending.

Airdried outdoors under cover, most woods dry down to an Equilibrium Moisture Content between 12 - 15%. That's more-or-less the bound water that's still in the wood. Take that indoors, into dry house air, and the MC might go as low as 5%. Sure, you can expect some movement.

To get zero water content, the wood needs to be dried at 101C (approx 214F) until it reaches a constant weight. Nobody here needs that but some lab work requires it.


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## Da Aardvark (Oct 11, 2012)

Yup.


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## Woodwart (Dec 11, 2012)

Uh-huh.


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## Brian T. (Dec 19, 2012)

What a TURD, like so many of my students in a past life, I have not answered your question. Sorry.

If you had wood, down to, say, 6%MC, and you put it into a humid atmosphere, yes, it will suck up moisture. The time it takes depends on the thickness of the wood (diffusion path length stuff).

If I dropped $15K on a Martin or Taylor guitar, the woods are thin. You can bet your last dollar that I'll have a humidifier in the case.


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## ETWW (Mar 27, 2011)

bberchin said:


> Question for you all with experience here- can wood that was dry pull moisture back in when it's stored in a cold, sometimes damp place even though it never comes in direct contact with moisture? What about climate change- cold to hot- will dry wood be effected enough to expand and contract?


Wood is hygroscopic. It will absorb or desorb moisture depending on the relative humidity of it's environment.

Temperature has little direct effect on wood movement although it does affect the rate of moisture transfer.


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