Time and Temperature to Kill Bugs

Advice on heat treating for pest control. October 17, 2012

I want to heat treat lumber to kill insect infested boards. I am not interested in drying the lumber, just heat treating it for couple of hours. I want to build an insulated box with heater that would permit me to raise the temperature. I have lots of questions about this.

What would be the desired temperature schedule for 1" and 2" thick planks?
Should green lumber be treated differently than half dry (~20%) lumber?
Is there any chance of checking/warping?
Should the ends be sealed?

I should specify that the box will only accept a maximum of 5 to 10 boards. It is really a small shop project to salvage some very nice wood.

Forum Responses
(Sawing an Drying Forum)
From Professor Gene Wengert, forum technical advisor:
Species? Generally 165 F air temperature until interior of wood is 133 F. 12 to 24 hours or longer.

With green lumber, same objective - 133 F, but time will be longer slightly.

If very dry, probably no checking risk although old checks can reopen. Warp is possible if the MC changes. Use an EMC close to the MC if quite dry. A tight box will do this with no effort.

End sealing not needed at low MCs.

From the original questioner:
The lumber is sugar maple. If I understand correctly, if the box is air tight, the lumber MC variation will be minimal, so it is unlikely that the lumber cracks or warp regardless of lumber MC.

Gene, I am not sure I follow your advice. Should the air temperature inside the box be 165 F for the full 24 hours or just until the wood gets to 133F, then lower the inside air temperature to 133F? I don't have any means of knowing the inside temp of the lumber.

From Professor Gene Wengert, forum technical advisor:
The temperature is kept at 165 F so that the wood is at 133 F for an hour. The time is a guess for you without something to measure it.