Workers removing a pallet of wood from the freezer.
Upon discovering a big infestation of powder post beetles in a stack of wood in his shop, Northern California woodworker Greg Zall found a creative and inexpensive solution to deal with them: An industrial freezer.
For $100, a cold storage facility near his shop loaded a pallet with around 500 board feet into its deep freezer and kept it cooled to sub-zero temps for three straight weeks. Zall–with whom I just wrapped up a photo shoot earlier this month–figured it was worth the trouble to load it up and freeze it because his stockpile included some less common woods like narra, pear, nutmeg, and elm. Plus, he wanted to see if it really worked, he told me.
Zall said he decided on freezing the wood after hearing from other woodworkers who had good results. It was also the least expensive and easiest option, he said. The others were to drive the wood to a fumigation chamber at the Port of Oakland–about an hour’s drive from his shop in Petaluma–which would have charged $300 to treat the wood. The other was to heat the lumber in a solar kiln, but he figured he would need to get it to 130 degrees for about seven hours, a temperature that was only realistic on the hottest days of the year. “It seemed like a messy job,” Zall said.
As a test, Zall resawed a small, infested board in half so that he could see a couple of beetles. Then he taped the piece back together and put it with the rest of the wood in the freezer. When he picked up the wood, he checked the test piece and, sure enough, the beetles had been killed. A few other cuts in some test pieces confirmed the beetles were gone, Zall said.
Any one else ever tried this method? How did it work out? Let me know in the comments.
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Workers removing a pallet of wood from the freezer.
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Close-up of infested board
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Zall circled the cavities where beetles were found and then checked to see if they were still alive.
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Another close up.
Comments
hey everyone i live in jacksonville florida and ijust bought some locally sawn pine from a guy and alot of it has pretty bad infestation.I thought maybe the person who sawed the boards might have taken care of the beetles himself but realized when i was building a project that saw dust kept coming out ofsome of the holes.so basically i want to know if there is any other way of killing these little pests.I dont have a freezer big enough for my boards.The boards are about 16 feet which is way to long to put in my fridge at the house hahaha and i dont think my dad would like that to much.thanks again im pretty newat this blogging stuff and reponds would be awesome thanks.
Used to work in the food industry - we never considered freezing an option when dealing with bugs. Yes it gets the active critters but what about their eggs? Would be a disaster to have them hatch out start chomping on one work. Heating to 140 deg F works as does methyl bromide but as mentioned there may neither considerations. At least check with your university extension office or a pro exterminator.
My question to you is how about the eggs that have been layed in the wood. I am not sure the freeze method will distroy the eggs. I am open to others comments and tests in this area too.
I recently did a restoration job of a dining Room table that had a pretty sever case of powder post beetles as well.
I had it loaded in a kiln for 3 weeks at over 150 degrees.
This insures that even the eggs are killed.
I believe the kiln method is truely the only way to eliminate the complete problem.
I also totally fumigated my shop when we realized this wood was filled with active powder post beetles. I then kept the shop shut tight for over over night before opening back up in the morning for business.
Hope this helps
What doesn't work: I rough turned some bowls from a very old coast live oak (California). I tried drying them by soaking in denatured alcohol for a week until they stopped losing weight.
After finish turning, sanding sealer and waxing I set them on the counter and a few weeks later plumb little bugs came out of new tunnels about 1/8" in diameter.
What does work: A few trips thru the microwave until the bowls were too hot to handle.
I have a question to consider. when any thing is frozen, the moisture in it expands, this may, or may not take care of the bugs and there eggs, but what about the ruptured cells in the wood. How will this effect the normal processes of expansion and contraction in the finished project?
A guy on a forestry forum told me to use Tim-bor spray. It's pretty cheap. I sprayed it on a few weeks ago, but am still seeing some piles of powder on my wood. It does say on the bag that some etching of the wood may continue until all the bugs are dead, but I'm not sure how long that will be.
Does anyone have any experience with this?
@UnseenWombat,
I've used Tim-bor. I haven't done any real side-by-side tests, so I can't definitively say that Tim-bor worked when the no-treatment option would have failed, but I can say that nothing that I've treated has shown signs of post-treatment insect activity.
If your wood is heavily infested, I think you have to get the treatment well down into the holes. Tim-bor is basically just borax, so it's a very mild insecticide, and the insects have to ingest a significant quantity for it to be effective.
-Steve
Most surface treatments, unless they are glycol-based, heavily applied and soak in, will only kill the beetles as they emerge. But they will also prevent new eggs laid on the treated surface from hatching and burrowing in - and kill them.
Remember, when you see the holes and sawdust - the beetles are gone. They are emerging - not burrowing in as many think.
They burrow in only when they are tiny, tiny larvae. A year or more later, after metamorphosis, they emerge as beetles and fly off.
KNOTS does have a couple threads on homemade borax treatments etc.
Here is from the University of Kentucky,
"The above chilling procedure generally is effective in killing all pest life stages, including eggs"
http://www.ca.uky.edu/entomology/entfacts/ef640.asp
as far as the wood goes. I have used plenty of frozen wood that was air dried outside it will not effect the wood in any way.
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