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Thread: Kiln drying to kill powder post beetles

  1. #1
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    Kiln drying to kill powder post beetles

    I have a homemade kiln I'm trying to sterilize wood in. I have got the temp up to 125 f. Hoping to get it to 135. How long will I need to keep it in there at 125-135 to kill any and all bugs. I do have a 2 slabs that are maple and about 3 in thick in there.

  2. #2
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    Sep 2013
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    Wayland, MA
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    According to the classic paper, 130 deg F in the center of the boards for 1-1/2hr will do the trick. Probably longer at a lower temp or shorter at a higher temp will work as well. They note that 130 deg for 30 min is not sufficient.

  3. #3
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    Is there a rule for how long it take center of board to get to that temp. It's been 135 over night. Is that good?

  4. #4
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    I would go longer for slabs that thick. I find that much depends on the moisture content when you started. I have a Greenlee electrical tester with a long wire temperature probe that I put in the stack and sometimes into the center of a sample. The wire reaches outside the kiln and I can monitor the internal temp with out opening or unstacking. I keep wanting a wireless version. My B.I.L. has one that allows him to see the inside temp of the meat in his smoker on his smart phone.
    Last edited by Maurice Mcmurry; 09-20-2022 at 8:56 AM.
    Best Regards, Maurice

  5. #5
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    I bumped the temp up to 150 this morning, should 24hrs be good to be safe? Moisture content is moderate (didn't test it) they have been air dried for years, but have been stored outside (under cover) for a year while my new barn was built.

    it has been at 130 for at least 24hrs.

  6. #6
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    Oct 2007
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    If you've been at 120 for 24 hours and then increase the temps in the kiln to 150 for 24 hours, you should be fine. USDA specs for sterilizing are for all parts of the lumber to hit 133F. They don't have to be kept there - just all parts need to reach it. Most DH kiln operators will finish their kiln cycle at 120F and then crank the temp up to 150F for 24 hour for sterilizing.

    MC% of the lumber makes a difference on interior temp - same as baking a cake. The drier the lumber, the faster the core will get up to temp.

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