"Freeze Drying"

Does any one have any experience with stored timbers that are exposed to extreme cold temperatures ( 0 to -30 F) and the drying effects: "Good" "Bad" any info would be appreciated. Thank You

Hi Akwood
Well here is my 2 cents worth on this subject
--not much drying will take place when the timber are in a frozen state
--Historically the timbers were cut in the winter time when most of the sap had decended into the roots of the trees, but having said that remember that depending on the type of tree some do not have sap, and retain their (evergreen) characteristics through the winter.
--Hardwoods, are better cut in the winter, Ie: less moisture to contend with, and the lumber piled and covered for 1 year for every inch of thickness--rule of thumb!
-- round timber should be cut in the cold part of the season, sawn or hewn before spring, and then piled and cured for 1 or 2 seasons --with a cover of boarding (to keep the sun off), and piled one on top of the other using the weight to prevent twisting during the drying process.
NH

I agree with NH, mostly, but also see a few other things in our yard. Usually, more drying is better as long as you protect from sun and quick drying so don't hold back. Certainly no "bad" things happen letting a timber sit in the cold.

Old logging stories talk about trees "blowing apart" in real cold snaps, wonder if it is due to real dry humidity condition or to expansion of held moisture? Mostly happens to birches which are real weak anyway.

I find wood dries more than you'd think in winter time. Any sunny day pulls out some moisture and the low (really low in cold weather) relative humidity forces moisture out, even by sublimation (direct from solid to gas). I think the relative humidity is much more important to look at than temperature.

We like to dry cants 9-12 months ideally, with open sides and covered top in an open area so wind gets thru.

A good reference on air drying from the Forest Products Lab, http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr117.pdf

Many tables including seasonal and regional drying rates.

All I know about frozen timber is that today the wood isn't 'carving' - it's shattering, and throwing fragments like broken glass!!

Pete