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Drying White Oak to 12%

Started by DR_Buck, December 15, 2019, 09:55:38 AM

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DR_Buck



I have a customer that brought a load of white oak logs to be milled and dried.  He plans on using the lumber to restore an old horse barn.   The barn is in the open and has no heating, cooling or insulated rooms.    I suggested to him that he really didn't need to dry the lumber fully as it would only regain moisture once put up.   I told him he could just sticker it until he was ready to do the work in the spring and it would probably be dry enough by then.   He insisted on drying, and since its more money for me, I agreed.   We decided that drying it to remove most of the water and stop at around 12%.   He thought this would be ok and it would make the boards lighter.

I'll still run a high temp sterilization cycle at the end to kill any bugs.   Is drying to only 12% a good plan for lumber being used for this purpose?   I assume its OK to dead stack and not sticker at12%, since I've done it before and had no issues.
Been there, done that.   Never got caught [/b]
Retired and not doing much anymore and still not getting caught

GeneWengert-WoodDoc

I see nothing wrong with what you said and what you are going to do.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

GeneWengert-WoodDoc

the Issue will be stopping at 12%.  Some pieces will be drier and some wetter if you stop at 12% average MC
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

Brad_bb

I'd just air dry it for 1-3 years.  Not sure how long it will take to get to ambient. 

I also worry about warpage while drying.  I'd quarter saw it so it will stay much flatter.  Hopefully the logs are grade logs.  I'd prefer to not have any sapwood on the boards either.  I don't saw much oak.  I'm getting ready to quarter saw a few thousand BF though.

You could dead stack if storing inside.  If not, keep them stickered.  You just don't want any moisture getting between the boards and causing mold/mildew or mushrooms.
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WDH

I never have any trouble getting white oak to stop drying :D. 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

K-Guy

If you are worried about getting it all to 12% you could do a slow cool down by turning off the kiln and leaving the fans running. It will equalize more that way.
Nyle Service Dept.
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GeneWengert-WoodDoc

One option is to run the kiln at 11% EMC or maybe 10.5% EMC.  The outer shell might get down to 11.5 % to 11.0% MC.  The core will be wetter.  If you are drying at 120 F, the core will be 5% MC or more wetter than the shell and not get much drier very quickly.  If you dry at 160 F, the core will be within 1% MC within 3 to 7 days.  In other words, hotter means more uniform MC and you will achieve that faster.

Because oak is a very high shrinking wood, it is important to get it very close to its final MC to avoid warp other shrinkage after installation.  In much of the US and Canada, the outside is around 12% to 13% EMC on the average.  The inside of the barn will be a percent or two drier, assuming there is no added heat.  

Also, to avoid moisture problems, use a water repellent finish to prevent rain wetting.  

Avoid any construction technique that would trap water.  Avoid contact with the ground, as ground contact will create decay risks even with white oak.  Rain gutters can be helpful.  Slope so the ground so that rain is drained away from the barn.  It is probably too late to consider a wide roof overhang..
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

DR_Buck

Quote from: GeneWengert-WoodDoc on December 19, 2019, 05:52:39 AM
One option is to run the kiln at 11% EMC or maybe 10.5% EMC.  The outer shell might get down to 11.5 % to 11.0% MC.  The core will be wetter.  If you are drying at 120 F, the core will be 5% MC or more wetter than the shell and not get much drier very quickly.  If you dry at 160 F, the core will be within 1% MC within 3 to 7 days.  In other words, hotter means more uniform MC and you will achieve that faster.

Because oak is a very high shrinking wood, it is important to get it very close to its final MC to avoid warp other shrinkage after installation.  In much of the US and Canada, the outside is around 12% to 13% EMC on the average.  The inside of the barn will be a percent or two drier, assuming there is no added heat.  

Also, to avoid moisture problems, use a water repellent finish to prevent rain wetting.  

Avoid any construction technique that would trap water.  Avoid contact with the ground, as ground contact will create decay risks even with white oak.  Rain gutters can be helpful.  Slope so the ground so that rain is drained away from the barn.  It is probably too late to consider a wide roof overhang..
If I do either one of these suggestions, I assume I should stick to the white oak drying schedule until I reach the 11% EMC, then move the temperature up?
Been there, done that.   Never got caught [/b]
Retired and not doing much anymore and still not getting caught

GeneWengert-WoodDoc

Yes, that is the idea indeed.  This procedure was used for drying oak bending stock, so it does work.
Gene - Author of articles in Sawmill & Woodlot and books: Drying Hardwood Lumber; VA Tech Solar Kiln; Sawing Edging & Trimming Hardwood Lumber. And more

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