# Cold Weather Milling



## kenkrizan (Jan 25, 2013)

A couple of questions:

First- When air drying lumber, does it continue to dry in very cold temperatures, such as -10 to +20 degrees F. Is the dryng process evaporation or sublimation or a combination of both?

Second- Is there any harm done in sawing a log that has been soaking in sub-freezing and sub-zero temps for a while (i.e. frozen solid)?

My mill has been idle for about two months due to really horrid weather and I am really anxious to dig it out and start using it again. I also have a large amount of lumber stacked in a shed and am wondering if it is still drying, or just sitting there. I started building a solar kiln- but ti is on hold until spring.

Thanks
KenK


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## ETWW (Mar 27, 2011)

Very little, if any, drying will take place at those temperatures. Moisture in the wood will be frozen and the RH is too high. Evaporation is what dries wood. Temperature, RH and air flow determine the drying rate. 

There's no harm to the wood in sawing it frozen.


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## bzguy (Jul 11, 2011)

Wood continues to dry in freezing weather if the ambient air moisture is lower than the wood.
Freeze-drying takes place in your home freezer, everyone has seen freezer-burned food.


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## Allen Tomaszek (Dec 11, 2010)

Hi KenK. It's perfectly safe and a commonvpractice to saw in the winter even when your logs are frozen. Your wood will be fine. It will continue drying but at a much slower rate than when temperatures rise and rh decreases. I saw and stack lumber all winter as time and weather permits. We just got done sawing some cherry logs in the past couple of weeks. Good luck with your lumber!


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## kenkrizan (Jan 25, 2013)

Thanks to all who replied to my post. The initial post was over two years ago when I was still new to milling lumber, but I've learned a lot since then.

Allen, everything you've said is absolutely true. The RH here in the winter is very low and the wood does continue to dry.

Ken


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## kenkrizan (Jan 25, 2013)

I've sawn nearly 600 bd of cherry lumber recently and I still have 11 logs to saw.

This year is not nearly as cold as the past two years.

Ken


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