Drying Very Large Oak Timbers
Big timbers should dry very slowly, and even then, the wood may be damaged. May 3, 2011
Question
We are currently looking into drying large volumes of 6" thick x 9" wide red and white oak beams. Are there schedules for drying thick stock like this? How long from green would it take to get a moisture content of 8%?
Forum Responses
(Sawing and Drying Forum)
From contributor K:
That shouldn't take more than a decade or two. But the degrade will be ferocious.
From the original questioner:
Well, I was hoping it would take a little less time than that. Currently we are only drying a few thick items such as 8/4 hard maple, hickory, cherry, and ash. Should it be air dried down to a certain percentage before kiln drying to get the best results? Is it possible to get the core dry down to 8%? I wonder if it's necessary to dry the core to 8%?
From contributor S:
It's most likely to crack no matter how you dry it. The slower, the better.
From contributor K:
Is it necessary? That depends on what you wish to use them for. The core will be riddled with honeycomb, regardless.
From contributor R:
The best thing to do is get a log and saw it into 2'' lumber and mark them to be in order the way you cut it, then kiln dry and after that plane them and glue them together the way it was. If you do a good job, you won't even tell it's been glued.
From contributor A:
RF vacuum kiln would be the best and in the long run, the cheapest, if you really need to dry them. Other vacuum kilns would work, but loading and unloading the timbers would be a lot of work.
The railroad tie place stacks them so they can air dry for a spell, and then sticks them in a steam kiln and cooks them before they treat them. Not sure how dry they really are before treating them, but they are just railroad ties, and so long as they do not bust apart, are used.
I dried some 3 inch oak in my Nyle and it took twice as long as 8/4, and I had to go really slow bringing up the temp. It would dry so much, then stop, and several times I had to add water to the kiln to condition it so it would dry down farther. It was all qsawn and came out with no problems, and is now the front door for a big home down on the White River.
