Powderpost Beetle Wood

Darren Wright

Staff member
Springfield, Missouri
So, much of the barn down at the farm has tiny little holes throughout the timbers and siding. There is a lot of siding that I'll be taking off of the lean-to that is covered in small holes, most likely caused by powderpost beetles. Most of those boards are around 6/4 and still in good condition otherwise.

Anyone used any of the pesticide products, such as Tim-bor or Boracare to treat lumber?

I realize that these both soak into the wood, so I'm more concerned about finishes that may be applied later. Both will leave a salt like residue, but if I removed the top layers using a planner I'm hoping to use some for furniture, obviously not for cutting boards and such. I think the bora-care is a glycol base that helps it soak in further, so leaning more towards the Tim-bor product, though both do need to soak in deeply to do the job.

I know it probably can be killed dried for a while to kill them as well, but I doubt I'll have a kiln built for it anytime soon and don't want to transport the wood anywhere unless it is treated.
I might slap together a redneck plastic sheet kiln, if nothing else it would keep them dry for storage... and it _might_ get hot enough to kill some stuff.. (a couple cheap logging thermometers would tell you)

I believe tim-bore is more likely to re-crystalize without the glycol... which may affect finishes more.. being held in solution is sort of a feature i think.

I also have these two homebrew recipes in my "list of handy links"

and this ancient sawmillcreek thread

Having attempted to put 20 mule team "regular" borax into solution to deal with a soil boron deficiency if I was going to attempt a homebrew version I'd probably start with the agricultural solubor product or one of the cheaper knockoffs of it.. (you can see the %'s and composition here: https://agriculture.borax.com/products/solubor)
I've never tried it on wood, but corn cribs used to be fumigated with High Life. I don't know if they even still make it. It's heavier than air and I used it to kill cut ants. If you covered the lumber with plastic and put a few open containers of High Life around under it, it would likely kill anything that was under the plastic.

It wouldn't affect the quality of the wood by soaking in or leaving a residue.

Powder post beetles have invaded my buildings and damaged most wood I have tried to air dry. With one exception they are generally a cosmetic problem that some people like. I have never had them in my home or workshop. But my outbuildings and air drying quarter sawn oak and poplar are enough to make you cry. My exception is a 30x30 garage that I built poplar trusses in 1980. The trusses look fine but they are like a sponge inside. They are rough cut 2x4s that can be broken anyplace with one whack of a claw hammer. I have scabbed pine along side them until I can get them totally replaced. The pieces seem to weigh less than half of what they should. I do not know how I have avoided getting them in my shop. My best guess is I am meticulous keeping the humidity below 50%. I think they like it higher than that.
Don't know what they used, but we had to fumigate all woods going to Australia.... we would contact the fumigation company, they would cover the cargo with a tarp and set off a bomb under the tarp or inside the freight container and give us a certificate.... not sure what we were fumigating for, but all shipments destined down under were fumigated..... you might call around one of the fumigation companies and see what they can tell you about the beetles.