Powder post beetles in a finished project, need help!

[Wes Billups]

I'll preface this by saying I've done a bunch of research on this forum and scoured the internet and can't find a solution to this problem.

Three years ago I finished a waterfall desk for my daughter from a large slab of Kentucky Coffee Tree. The slab had evidence of insect infestation and the sawmill assured me it had been kiln dried so I thought I was good. All of the holes and channels were filled with epoxy during the manufacturing process. Overall I think this slab sat in my shop for 3-4 months before finishing the desk and bringing it into our house. Never did I see any evidence of live infestation.

About a year ago my daughter mentioned that there was a hole the front edge of the desk. Upon inspection I saw no dust and incorrectly chalked it up to epoxy failure and figured it had just popped out of the hole due to seasonal wood movement.
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Fast forward to last night at dinner. She mentions she had noticed a couple more holes. Of course my heart sunk and I immediately inspected the whole thing. I found these other holes. Based on my research I believe they are powder post beetles although I don't see the telltale dust in the hole. My guess is it's been worn away as this is her remote learning desk which she spends 7-8 hrs/day at. All of the exit/entry holes are on the front edge of the slab and all contained within the sapwood (1/2" - 1") from edge.
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Looking for help on how to get rid of the beetles but more importantly, should I be worried about the house?

I didn't sleep well last night so any support, suggestions you guys have would be appreciated. I don't mind ripping both edges from the desk and in essence remaking the waterfall to mitigate the active beetles. My bigger concern is about the other wood in the house. One positive I read is powder post beetles tend to stay in hardwoods which hopefully would mean they should stay out of the house structure but there is a lot of other furniture in the house.

Thanks,
Wes

My rese

[Clark Hussey]

The first thing I would is get the desk out of the house. If you have powder post beetles. No amount of cutting or plugging unfortunately is going to get rid of them. Hopefully someone has a solution to this. You should get a pest exterminator to treat your house. Good luck on this.

[roger wiegand]

1) 135 degrees for eight hours (IIRC, check the USDA web site)
2) fumigation with methyl bromide (you'll need to take it to a licensed pro facility, most "pest control" companies can't do this)

PPB are ubiquitous in our part of the world, they seem not to attack finished pieces. We'd be treating our house 10 times a year if we called an exterminator every time we ran across them in a piece of firewood or whatever. I had massive damage in particular boards in my barn, spraying the entire structure thoroughly with Boracare seems to have stopped them along with replacing the most infested wood.

[Bradley Gray]

I've good luck with Boracare also.

[Wes Billups]

Thanks for the suggestions. I will definitely get the desk out of the house and most likely just park it in the garage.

I'll be calling a pest management company as soon as they open up. I'm wondering if I can salvage the piece by injecting a product like Boracare into the holes and just keep the desk in the garage until I stop seeing evidence.

Might try to find a source to bake them at the 135°F Roger recommended but not sure where I'll find such and oven nor what it'll do to the finish/glue.

Keep the ideas and suggestions coming.

[Jon Grider]

Timely question. I have a piece of beautiful curly cherry that had ppb. That's had not has, at least that's what I'm shooting for. My solution last year was to expose it to a quartz radiant heater, the kind that heats objects rather than air and starting from the most infected end, moved the board along under the heater after each section was exposed for about an hour iir. The wood was very hot to the touch, easily surpassing the 135 degree f mark. Several hours to treat both sides of a rough sawn 5/4 9' board. I isolated the board and yesterday had a look. No frass, no new activity that I can discern. I'm cautiously optimistic that this worked but will wait until next year to use the board. This may be a fix for your desk, though your rmv.

[Bill Dufour]

It may have been infected after you made it. A powder coating oven or a car paint baking oven would work. But unless carefully regulated they may overheat the glue and finish. Heat too fast and wood may warp and pull joints apart? How hot does a dry sauna get?
Bil lD

[roger wiegand]

A hot attic on a hot summer day can do the trick-- or a glass-windowed van parked in full sun with the windows closed in the summer easily gets that hot.

Most sawmills that dry lumber heat treat in their kilns to meet the required spec-- if you have a pallet factory anywhere nearby that makes pallets for export they surely do it.

[Jim Becker]

So other than the last photo, those recesses appear to have been there when the top was cut/milled. The fact that there's no frass makes me wonder if you really have an issue or there was just a thin area that broke way with use. Active insects tend to push out the dust and you usually see piles of it under the holes. But of course, minute mounts could disappear with regular room cleaning and might not be notices. Personally, I'd monitor it a little under controlled conditions to see if you actually get any leavings appearing from those holes before you write the thing off.

[Doug Dawson]

You may be in luck! There was an article in the NYTimes within the past few weeks about Robert Caro’s office, in which he claimed that having a rounded inset in the front of the desk helped with his back problems while writing. This solution was recommended to him by no less than JFK’s physician, who advised JFK on ergonomic solutions to his back trouble. So... you could just cut out an inset on the front of the desk and discard the infected wood.

In case you don’t believe me: https://www.nytimes.com/2021/01/08/nyregion/robert-caro-archives.html?searchResultPosition=2

[Robert Mayer]

Buddy of mine had those beetles in his beautiful hickory flooring not long after it was installed. It was a nightmare for him.

[Erik Loza]

...Most sawmills that dry lumber heat treat in their kilns to meet the required spec--

This is the route I would go ^^^ since summer seems a ways off. Good luck with it.

Erik

[Richard Coers]

Boracare is a preventative, not an eliminator. 3 stages of PPB, adult, egg, larvae. The hole is the exit hole. The egg is laid in a crack or crevice, and the larvae bore tunnels in the wood to feed. Then it crawls out and breeds to continue the cycle. Any treatment to eliminate them has to address the 2 stages inside the wood. That's why the most proven method is heat, and that 133 degrees has to be to the center of the board. Most sterilizing kiln schedules heat to 150-155 so the board reaches 133 in the center. There has to be frass to be PPB.

[Lon Crosby]

Think about using TEMPO, a “safe” insecticide.

[Scott T Smith]

Boracare is a preventative, not an eliminator. 3 stages of PPB, adult, egg, larvae. The hole is the exit hole. The egg is laid in a crack or crevice, and the larvae bore tunnels in the wood to feed. Then it crawls out and breeds to continue the cycle. Any treatment to eliminate them has to address the 2 stages inside the wood. That's why the most proven method is heat, and that 133 degrees has to be to the center of the board. Most sterilizing kiln schedules heat to 150-155 so the board reaches 133 in the center. There has to be frass to be PPB.

Richard's advice above is spot on. Many smaller kiln operators can place your finished piece in their kiln when they do a finish off / sterilization run. I usually have customers bring me finished pieces 2 - 3 times a year for the exact problem that you have.

If the wood had a high MC% when the furniture was built (12% or higher), it will probably warp and distort during the sterilizing process. However, if it was dried below 10% MC you should be ok.

[Bill Dufour]

I used to hear radio commercials for the environmentally correct termite treatment company. I think they used liquid nitrogen to freeze the little devils. I suppose freezing and suffocating them from lack of O2.
Bil lD

[Wes Billups]

Thanks for everyone's suggestions. On Sunday I decided to go probably the most destructive route by ripping off both edges from the waterfall desk and then gluing on new wood to regain the lost width. My thinking behind this was all of the visible damage was in the outside 1" where the sapwood existed and I was worried baking the little critters would cause the waterfall joint to fail which would mean rebuilding the whole thing.

The fact I had a 2" thick piece of cherry on hand which was perfectly sized to replace the lost wood finished the decision for me. I cut the edge with the most damage and had to rip it three more times, taking 1/4" with each pass, until I say no evidence of tunnels.

This was after the first rip pass approximately 3/4" in from the live edge where a beetle had popped through the finish. I kept cutting until there were no more holes. Ended up taking about 3" off of the front edge and only 1" off the back edge.
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The cherry board I had to rebuild the width was 6" wide so the modified desk will actually be deeper once I'm all done. I think it'll look pretty nice with a darker 3" boarder on both edges with the Kentucky coffee wood in the center. I did finish machining, gluing, and sanding all on Sunday night. I'll post some pics after the finish is applied as it's pretty "blah" right now.

Out of curiosity I cut across the grain at the biggest hole and confirmed it was definitely powder post beetles. All cutoffs from the desk were burnt in our firepit Sunday evening as well.
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*Red circles signify the same hole.

[Tom Bender]

133 is not all that hot. (hot attic in summer, hot car) You might just want to make a temporary box with sheet goods and a heater to be sure before you add the Cherry. You will want to insulate the floor of the box and maybe throw a blanket over the top.

[David Utterback]

Tom's idea is what I was thinking and using sheet insulation material for the box. You could also possibly use a few incandescent lights for heat source.