Powerpost beetle and Bora-care

[Tim Johnson]

I have secured some air dried oak that was essentially free, at $0.11 bf, but I noticed while unstacking and loading on my trailer for a trip to its new home that there were ocassional piles of "flour" and pin holes in a few pieces. I have removed these obvious bad boards and will be making smores with the coals from them soon. This wood had been setting inside for two years. My search revealed that Timbor or Bora-care were recommended treatments. My question is, if I spray each good board down with the Bora-care solution, can I safely move it inside after treatment, or should I just make firewood? This would be a shame due to the large number of very wide, thick boards in the stack, but I also realize that I can't afford to contaminate my existing hoard of boards.

Does anyone have experience with this product and it's ability to eliminate the problem?

Thanks in advance,
Tim

[Richard M. Wolfe]

The borate treatment is good for keeping insects from getting in the wood but it will not kill the larvae (grubs) that are in the wood - the treatment will not penetrate deeply enough to affect them. The borate acts as an internal poison; the insects lay their eggs on borate treated wood and the larvae in boring into the wood ingest the uppermost treated wood and don't get very far before they die.

I have had red oak that I know was kiln dried get infested with powder post as the wood sat long enough to take up enough moisture from the air to make it susceptible again. One of my pet rants: Just because it has been kiln dried doesn't make it bulletproof. The best way to make sure it is bug free and will stay that way would be to heat the wood again (kiln it) to about 130 degrees for 4-6 hours which would kill anything in the wood and then use the borate treatment to keep it from being re-infected.

[andy Needles]

I use lots of air dried wood here in California, and Borate does not penetrate dried wood well. I would soak it at least three times, and let it set, to see if the bugs keep popping out. . I would also consider using detergent to help with liquid penetration.

[Frank Drew]

Tim,

Have you noticed bug holes much past the sapwood? If not, can you just cut off the affected edges of the boards?

[Tim Johnson]

Frank,
I've not paid real close attention to the amount of sapwood in the entire stack, but I did look again at the pieces I have already removed and some of them have a large percentage of sapwood. Do you think that reducing the sapwood portion will reduce the likelyhood of active pests?

Also, if the beetles are still active, will I continue to see the little "sawdust" piles on the boards, or once they get inside, will evidence of activity decline as they continue to do internal damage to the board?

Thanks,
Tim

["Gary Brewer"]

Tim: I went through this with a beautiful batch of wood my son got me from a friend of his last year (walnut, cherry mostly). I had the pile in my garage and every day I had new little piles of conical saw dust. It really freaked me out. I found out I had powder post beatles and they also liked old furniture which I have. I trimmed like mad the sap wood that had 90% of the holes and treated the rest with some very expensive bora-care product that had an alcohol base. This was very expensive, around $100 a gallon and then I treated my storage area also. A total of two gallons worth. After all that I bumped into a local sawmill / lumber seller owner who said that 140 degrees in a kiln for 8 hours would kill anything in them. He said he would charge me $30 a load for his small kiln. I would have needed two loads. Had I known this I could have saved all the lumber, a lot of time, and money. If it ever happens again I'll take it to him for sure. If you can find a small operator who will accommodate you it would be the easiest thing. The borax product seems to have worked but it did leave a film on the surface and penetrated a little bit. The non-alcohol base product is a lot cheaper but I couldn't buy it in New York State and it doesn't penetrate as well. I haven't made anything out of it yet so I don't know if it will effect the finish or wood color.

[Richard M. Wolfe]

For people who have a question about the borate trreatment and finishing before I bought any of the current treatment I have now I spent some amount of time on the phone being reassured by the people who marketed it that it in no way has an effect on stains or finishes. Anyway, a little sanding or especially planing will get rid of any of the borate. Wet a board liberally with about any water based solution (like water based varnish) and see how far any of it penetrates the wood - not very.

[James Ashburn]

The effectiveness on stopping an active infestation of PPBs with chemicals applied to the surface can be debated BUT do you really want to breathe the microscopic dust laced with chemicals when you go to use the wood? I certainly would not and I would never want to purchase wood from any supplier that chemically treated their wood.

Another problem with chemicals is that the eggs and larvae can stay in the wood for years before they emerge to mate. If you have already built furniture and put it in your house then you could get mating adults in your house. The only thing that can treat to the center of the board is heat.

I had a similar problem with some mesquite I harvested from logs. I built a small kiln using sheets of insulation from Lowes and used a floor heater and a heat lamp to provide heat. I bought a small stick type thermometer that I just pushed through the insulation and regulated the temp manually. After a couple of hours (my guess at how long it would take for the center of the wood to reach at least 140 degrees) I opened it up to find many small dead little PPBs.

Good Luck,
James

[Cliff Rohrabacher]

Cobalt 60 will do the trick.