Home wood kiln – temp and time for insects
madphilip
| Posted in General Discussion on
I have a small wood drying kiln, about 6′ long to take lumber that is already air dried to around 12-16 percent down below 8 percent. So the boards are about 48″ long, in this case sweet gum milled ranging from 4/4 to 8/4. Stacked and stickered, of course.
To treat for possible insects, I added some heat bulbs. The box temp has held steady for 24 hours, always between 150-160 degrees F. Should this be enough time already? Having trouble finding definitive information. Thanks!
Replies
But what is the core temperature? For termites they say 130 degrees f. Maybe with a meat thermometer you could find out? Beetles I would think would be tougher. Tardigrades your not even close!
I've always been a little dubious about these types of treatments for insects though there are commercial companies that specialize in doing that. Once I was in an attic crawl space and the temperature had to be in that range. Maybe because the heat had forced them out of the wood there were swarms of termites but it appeared to me that it looked like they were having a block party, they were far from dead!
Thanks. Your question, I think mirrors my own: how long does it take to get the core temperature above 130, and how long does it have to stay there?
Shannon's Lumber Industry Update podcast has a lot of episodes where this is discussed but I don't have specific episodes I can recommend. Should be too hard to find there as comes up frequently.
Thanks. I started listening to that one recently, but didn't know he covered this topic. Perhaps some homework is in order.
This USDA study appears to provide the answer, if I'm reading the conclusions on the final page correctly. Interested to see if others read it differently.
"The time to heat the center of five hardwood species...to 133 F...with a nominal heating temperature of 160 F...with times as short as about 15 min for 1" thick boards to almost 300 min for 6"x6" square timbers..."