# Powder Post Beetles In A Finished Walnut Chair



## gfadvm (Jan 13, 2011)

I searched all the previous threads on this topic and didn't get a definative answer so I'm posting this. I recently built a walnut folding chair, finished with several sprayed coats of Spar Urethane, and sold it for a good bit of $. The owners report tiny holes with bits of sawdust have appeared. I want to do the right thing but they aren't looking for a refund if it can be fixed (bugs killed) or I'll make them another but I still need to know what to do to kill these critters if possible. Calls to several exterminators have not produced any answers as they don't know what to do either. HELP! Edit: This was supposed to be kiln dried lumber so I don't know where these came from and I haven't seen any other damage in my shop?


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## rance (Sep 30, 2009)

Put it in a microwave for 5min on defrost.

or

Fumigate it for a few days and then test it/give it back.


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## longgone (May 5, 2009)

Rance…you must have one huge miscowave if you can fit a chair in it.

Powder post beatles. They are a pain. I threw away a cabinet once that had them but I understand that there are options to get rid of them. i am not sure what they are but i have seen others post about their solutions.
Good Luck!


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## Timbo (Aug 21, 2008)

I bet if you put the chair in a big black trash bag and left it out in that Oklahoma sun it would be almost like an oven or kiln inside.


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## patron (Apr 2, 2009)

i don't know if it might work andy
but as it folds up

if you can put it in a top opening freezer
and let them freeze for a while
that may do it

if not wrapped in some plastic sheeting
with some exterminator powder 
or fumes might work
(like tenting a house)

good luck


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## reggiek (Jun 12, 2009)

Here is some info I've used before. They have some excellent information on Powderpost Beetles


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## SnowyRiver (Nov 14, 2008)

I would just put the chair in a large plastic bag or sheet of plastic, shoot some insecticide in it and close it up for 48 hours.


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## SuburbanDon (Mar 15, 2010)

I like the black bag in the sun idea.


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## sIKE (Feb 14, 2008)

You might try fuming with some amonia


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## Loren (May 30, 2008)

Find a place that paints cars, put in in the oven they use to
cure the paint. Any antique dealer who handles furniture
should be able to make recommendations to your client.


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## gfadvm (Jan 13, 2011)

Thanks for all the quick replys. Can I fumigate it effectively by bagging it and setting off one of those Raid bombs in the bag; then leave it bagged for a period of time? This is my problem NOT the new owner's so I need to deal with it. Thanks again my friends.


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## SnowyRiver (Nov 14, 2008)

I would just go to your local garden center and get some insecticide for powderpost beatles and use that in the bag.


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## SCOTSMAN (Aug 1, 2008)

I feel your pain brother , it must be very frustrating to have executed a piece of work and have this happen. I beg you not to worry yourself sick over it keep in touch with the people and some of these ideas will work. I would contact a local university or wood college and ask their opinion before starting on any of the frezing heating ideas they may make the damage worse or joints come loose etc take it easy and keep cool,after all it's not exactly your fault.Alistair


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## bruc101 (Sep 13, 2008)

About 8 years ago I was helping the finishing department for a small aerospace plant on a project for a couple of weeks. Three of us were in the finishing department one Saturday morning all decked out in our clean suits doing some serious work for one of their finishers who just happened to be a woodworker.

We had their drying oven set at 200 degrees for one hour. Inside the oven on the drying racks were 2 dozen 2×8's x 8 feet long full of the famous wood eating bug…at the end of the hour those wood eating bugs were no longer living…course we had some cleaning to do to purge the oven of dust.

So, heat does kill them.


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## Pono (Mar 10, 2012)

Those nasty powder monkeys I have had to deal with them constantly in hawaii last 15 years cut a nice tree they like they appear withn hours.

IF you have acess freeze it hahaha but it works.from there I have used thinner and all sorts of chemicals the best I have found is the bayer poison from homedepot make sure it gets in good.


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## LittlePaw (Dec 21, 2009)

Here's my five cent's worth, Andy. 1) KNOW SOMEONE WITH A WALK-IN FREEZER? Leave the chair in it for a few days. 2) disassemble the chair; put all parts in a big plastic bag and set off a bug balm in it and leave it alone for a day or 2 or 3 . . . until you hear nothing with your stethoscope. Hope for the best!


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## IrreverentJack (Aug 13, 2010)

+1^ On talking to an expert to find out what bug and what will kill it. Do you know they were in the wood when you sold it? You might have a bigger infestation than just a folding chair or maybe your customer has. Good luck. -Jack


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## jcsterling (Aug 1, 2008)

Had the same problem with a completed project in a clients home. After extensive research I found that fumigation rarely works as the eggs can remain dormant for long periods of time. What I found was that the best course of treatment was buiding a small "kiln" with 1" or 2" foam taped in the corners and a heat source (I used lamps) to get the temperature to 160 degrees for a minimum of 6 hours. You must also keep the humidity up so I placed pans of water and damp rags in various locations in the box and checked them regularly.. the second best option was a deep freeze (I believe 5 days). best of luck.


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## gfadvm (Jan 13, 2011)

Jack, Of course I didn't know it was infested when I sold it! I checked the remainder of my walnut stock and can find no evidence of infestation so I don't know where this came from. This piece had some sapwood that the remainder doesn't so that could be it. You would think I would have seen something when I was milling, building, and finishing this chair. John, This wood was stored in an unheated building when the temp here got to 25 below winter before last. You would think that would have zapped any bugs.


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## spunwood (Aug 20, 2010)

No expert, but you might consikder a spraying with borax (just water and borax mix). not sure how this would effect your finish though…trash bag variations and freezer all sound good. I am not sure heat alone would do much to them. Normally the bigs are dead if kept away from moisture.

Maybe the client has an infestation?

Good luck.


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## gfadvm (Jan 13, 2011)

I can't imagine that it got infested after I finished it as it has several coats of Spar. The little bastards must have been dormant in the wood when I built it. I'm also amazed that they can chew their way out through all that Spar. They haven't brought it back yet so I haven't seen it but it sure sounds like pp beetles.


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## kizerpea (Dec 2, 2011)

i had the same thing happen to a big project in my house with oak…went to lowes an got some terimite poizen mixed with a little water an brushed it on…no more dust in 10years


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## BilltheDiver (Jul 2, 2010)

I am a pest control professional at an Air Force Base. Heat will kill them, but you must get the temp up to at least 140 degrees inside the wood. Fumigation with either methyl bromide or Vikane will kill them but the rate is 10 times higher for powderpost beetles than for drywood termites. If you can locate a pest control company with a fumigation vault, this is your best option. Freezing for 3 or more days should work as well. Liiquid borax treatments are only effective if done prior to the finishing process and can take 3 years to penetrate to the center of a 4X4. Bug bombs are not likely to do any good as they do not emit a true gas, but only a mist, and that won't penetrate the wood.


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## Nomad62 (Apr 20, 2010)

The adults need a rough surface to lay eggs on, so the bugs it now has must have been larvae in wait within the wood. The only way to kill them is to heat the wood, and it must be at least 133deg f thru and thru to do so. Freezing will not kill them, nor will fumigation as the finish you put on will block the fumes or insecticide. Kiln drying is just drying, many kiln operators do not have a way to heat, or sterilize, the wood. Heating may cause the wood to move, make sure the environment you heat it in has a level of moisture to keep it from drying too far. Best of luck.


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## Scsmith42 (Jan 26, 2011)

The holes that your customers are seeing are due to the larvae hatching and boring their way out of the wood.

As Nomad stated, the core of the lumber needs to reach a temperature of 133F for at least 4 hours in order to sterilize it. This is the specification from the USDA Forest Products Labratory Kiln Operators Manual. This can be done by building the foam board sterilization chamber as JCSterling mentioned.

As long as you don't overdo it, your lumber and finish should be ok.


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## Cha (Feb 25, 2011)

You may try contacting a lumber yard that deals with hardwood. They have the same problem, I know because I have talked about it with them. They told me they kill the beetles buy Kiln drying but sometimes they get back into the wood and they have to treat the wood. What they use i do not know, but it is worth asking.


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## Knothead62 (Apr 17, 2010)

My son had them in his hardwood flooring. They had to pinpoint the different places they were showing up and replace the boards. So far, so good!


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## gfadvm (Jan 13, 2011)

I got the chair back yesterday and it appears the bugs are only in one slat that has a lot of sapwood in it. I soaked the whole chair with Viper insecticide knowing that this probably won't work but it was worth a try. I may just burn this one and build them another one if the insecticide won't work.


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## BilltheDiver (Jul 2, 2010)

Hadn't considered the finish blocking the fumigation from entering the wood. Good point!


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## Tango (Sep 2, 2008)

Get a syringe with a thin needle loaded with any termite poison and inject the liquid into the tiny holes. You can even inject alcohol or mineral spirits. I did this and manage to collect a lot of bugs from a piece of Cedar once.


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## gfadvm (Jan 13, 2011)

I got a lead on a powder coating company locally that has a big enough oven to 'cook' this chair if the insecticide doesn't work. Heating it to 150 for several hours should kill the little beasties and shouldn't hurt the finish?


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## Scsmith42 (Jan 26, 2011)

Doc, I'm a miller and kiln operator (who also happens to be married to a veterinarian that attended Oklahoma State in Stillwater). You don't need to go to 150F, and as a matter of face if you heat it too much you will get some unwanted side effects, such as chemical changes in your finish, etc. If you used shellac, you'll change the finish even at 133.

USDA Kiln Operators specifications for sterilizing wood is to heat it until the core reaches 133F for 30 minutes, or you can leave it in 125F for several days.

In my experience, for 4/4 - 8/4 lumber you will reach that temp if you set it in the kiln at 135 and leave it there for at least 4 hours after reaching temp.

Odds are, the ppb are already gone, as the holes are a result of the eggs hatching and the beetles burrowing their way out of the wood. There may be some unhatched eggs though.

As far as using the powder coating oven, if it uses some type of reflective heat (heat lamps), you may get mixed results because steel will absorb the rays and heat up, versus wood will not.

Do you get Fine Woodworking Magazine? About a year ago (December '11 issue, or thereabouts) they had a short article in back about sterilizing wood at home using foil covered foam insulation board (such as celotex) and a small space heater. This would work just fine for your needs. The main thing that you need to sterilize is the sapwood, as walnut heart wood is toxic for most pests.


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## Peter5 (Sep 22, 2010)

I had this problem really bad on a bed that I built. I posted the same question here. I bought a treatment from the DIY pest control people (linked above in another comment) and I'm waiting to see how it turns out. I was told it would take a few months to kill everything, so for now I'm leaving the bed outside in the yard and putting our mattress on the floor. I had an oil finish but I had thousands of holes from the bugs, so my hope is that the holes will give the poison passage way into the wood. We'll see. Let me know what you find out.

Pete


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## Grandpa (Jan 28, 2011)

My exterminator tells me the only way to get rid of them is to saturate the wood with Borate. He tells me it will kill the live ones and leave enough residue to kill the ones that hatch out before they can lay eggs. I have them in my firewood. He says that is the thing to do. I haven't done it yet but should before they look for a new cafeteria.

http://www.domyownpestcontrol.com/boracare-p-100.html


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## gfadvm (Jan 13, 2011)

Grandpa, I don't think the Borate would work as this piece is already finished with Spar urethane so the Borate can't soak in. I'm exploring ways to 'cook' the little beasties now. But thanks for the input. I'll keep you posted.


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