Log Drying and Degrade
Don't wait to long to saw ... but don't be too quick to write off an old log either. faOctober 4, 2011
What is the moisture content of fresh cut logs, and how much will they dry in a week or month? Is there a big difference in the moisture content of lumber cut from fresh logs vs. old logs?
(Sawing and Drying Forum)
From contributor A:
MC depends on the type of wood. Fresh cut logs do not lose moisture very fast. You can let a log sit for years and it does not lose much.
From Gene Wengert, forum technical advisor:
Some species will be 30%, some 130% MC when first cut. The ends will lose quite fast in warm weather - weeks. Likewise, where the bark is off there is a fast loss. Anyone that has sawn logs over a year old knows about insects, stain, maybe rot, and moisture loss that cause sawing problems.
From contributor X:
As said most species don't keep well in log form. Some are worse than others. You can't let a hackberry lie around very long or pine either. Walnut is a different story. Although it's not good to allow any species to stay in log form too long (unless you are spalting it and know how) walnut is very forgiving. So is osage and some others. The downside to sawing very dense species like osage that do keep well, is that every year it gets harder and harder. Osage that has been in log form for four years makes green Pecan (a very hard species to saw even green) seem easy.
I sawed some walnut logs in 2006 that had been laying in a field for five and a half years. They were left out in the sun but pasture grass had grown up around them. I got a lot of beautiful lumber out of them and the logs were still wet beginning about about inches into the heart. Most of the sap was rotted off and the logs were checked pretty bad, but I didn't have nearly as much waste as I figured I might. That's the exception though as most species will not keep past a season or two in log form without serious degrade or total loss.