Drying Half Logs for Benches

Unfortunately, large logs crack as they dry. It's unavoidable. March 16, 2015

Question (WOODWEB Member) :
I have made a number of half log benches in the traditional log-on-log style, most of them with either fresh cut logs from tree services, or with found logs. I've limited them to species that are rot resistant such as cedar and locust, but have also made them from oak, elm, and cherry, to name a few. A recent batch of logs I acquired were of Atlantic white cedar in diameters from 13"-15". Almost all of them had high moisture contents, usually above 20% and sometimes well above that. They started checking immediately, and as I worked them my heart began to tremble as the summer sun immediately began to cause large checks, with audible pops happening every few seconds.

I would like to identify whether or not it is possible to either air dry or kiln dry (either solar, steam, or vacuum) whole or half logs of this diameter in lengths up to 12' without significant checking or splitting. I've looked in the forums, and most posts indicate that checking is not an issue as long as water isn't taken in through the checks. The problem with outdoor benches is that they are fully exposed, and water can enter any checks or splits in their tops, regardless of finishes applied. I've tried applying a product called Pentacryl, which is a stabilizing agent but needs to be sealed with another product to prevent leaching, and this is only moderately successful while being very expensive and time consuming to apply. I've also tried applying a product called Petri Wood, which makes miraculous claims about "expelling" water within the wood and accelerating the petrification process artificially. This too is expensive and none of their claims are truly verified in large dimension timbers. Also, neither of these products allow me to seal the exteriors without locking in moisture, thereby "cooking" from the inside.

Does anyone know whether kiln drying large logs is either feasible or possible? I'd much prefer to mill them rough, dry them, and then complete them when their moisture level is suitable for traditional finishes such as tung oil, or exterior poly's. I live in the northeast, so solar kilning is only possible during the warmer months. I'd sure appreciate anyone's insight into this. I have to believe that something as simple as a log bench can be dried and protected without needing a fat wallet or a PhD.

Forum Responses
(Sawing and Drying Forum)
From Contributor P:
Would it be possible to make three radially deep cuts underneath along the bench? The cut would be so deep that about two inch of the flat top of the log remains solid. I think the log would in that way be less inclined to crack in the flat top surface.

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From contributor X:
Logs are going to check as they dry to some degree no matter the species or the drying method. Learn to incorporate the checks into your work and they won't bother you as much.

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From contributor Z:
If you can cut the logs about 2" below the pith and use that section should reduce checking to some degree.

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From Contributor B:
You're asking an awful lot for wood to work like that, in my opinion anyway. While it sounds as if it should be easy enough, the mechanics of it are a long ways from easy. The center of any log is juvenile wood, which is unreliable; it has less structure that wood grown when the tree is older and tends to split. You will no doubt see or know already that a center cut slab with the pith at the center will crack from the pith out almost every time, hence Dales response makes good sense; slicing outside of the juvenile wood should help. Trying to dry 8-10" thick wood is a person’s quest, there are no proven reliable means of doing so, at least in my quests; the tensions and limited water movement just do not allow reliability to be warranted. Logs at 20% MC seem really dry. Are you sure your moisture meter is set right? In the end, my only recommendation (as improbable of a realistic pointer as it may be) would be to cut your wood on the coldest, wettest days that you could have; the shock to the wood will be minimal. Sawing on a 90 degree day kind of asks for problems. Best of luck with it, sure hope you can come up with something that works.