Sterilizing a finished dining room table?

[forrestM]

I have a customer with a 6 year old walnut table that is showing signs of powder post beetles. They want to try and use my nyle l200m to kill the bugs. It is 7 boards glued together for a top and has a matte poly on it as well. I was thinking of putting it in the kiln at the end of drying some white pine when I am setting the pitch. Would 160 degrees ruin the table? Glue or finish?

Would just doing 130 degrees for 24 hours be a better bet? 

How likely are we to trash this table? 

[beenthere]

Taking chances that the heat will ruin the table, or at least spoil the finish. I suspect it could cause damage that re-finishing and flattening again would be required.

I'd let the pp beetles finish their job and then decide if a refinish is in order.

Sounds like the finishing job was rushed. Also, after this length of time, wonder if what is observed is really caused by the pp beetle. Some pics of signs seen would be helpful.

[Stephen1]

I have sterilized a few finished table tops in the IDry. Some have joints and some were 1 piece. I am not sure they were pp beetles but there was signs of insects coming out.  Most have seen the damage within 2 years, I had a pine FP Mantle that had borers . 
I usually put them in on top of a load and run it. The kilns hits the 160 around a week and then I pull it out. Damage?, slight movement, not nearly as much as what I expected. I never really noticed any Finnish damage. 
Remember, at one time it needed 134F for 1 hr at the core, now I believe that has been upgraded to 150-160 but I can not confirm that. Hopefully somebody else will comment on that. 
I also agree with beenthere in the 6 years, seems a long time for PP beetle, I always thought they showed up in a 2 year window. 

[YellowHammer]

I've done it twice, many years ago, with mixed results, but I use a DH not a vacuum so it my be more successful than my experience.  

Now I just tell customers that the best way to sterilize is heat, and if they bring someone's else's radioactive wood to me, I will sterilize it by throwing it in the burn pile.

I sure don't want the story to get out that I sterilize other peoples wood because the Sargent York efffect dictates that the third or fourth time the story is told it will be my wood that has bugs in it and I'm fixing my mistake.  Nope.  However, that is just me.  

It really needs 145F or 150F for 24 hours to be sure.  There is a high likelihood the finish will be ruined or at least soften, and any glue joints will move and likely the table legs and surface.  I'd give it a 100% chance of killing the bugs but a 50% chance of ruining the table.  I give those percentages because I've done it twice.  Once on a bench, once on a table.  Both moved a little, but the bench warped so bad it was trashed.  The table, it still warped some but not too bad, but the ironic thing is that when the husband and wife came to pick it up, she was so grossed out (I made a point of showing them the dead carbonized carcasses so they knew I did my job) that she told him to never bring it back in the house, sterilized or not because she was never going to eat off it again.  Quite the public argument, and it was pretty entertaining for the others customers watching.  Then she looked at me and asked or more like yelled "Does your wood have bugs in it?" And I answered back equally loudly "Of course not, I sterilize every single board!"  Then she laid into hubby again.  

BT is correct, many times people can't tell a PPB from a baseball bat, so pictures would be in order.  It may just be a fire drill.  

Dr Gene once told me the longest dormancy period for PPB's was 6 or 7 years, but 3 is not too unusual.  

[Larry]

PP beetles are pretty small and don't eat much. :D  I would just let them emerge and not worry much.  I read someplace they will not reinfect any wood with a finish on it, even wax.  I guess they can lay a egg in a fresh exit hole but a bit of of wax would keep that from happening.  If that is true, they will die out on their own without any intervention on your part.

[kelLOGg]

I sterilized a tabletop for a friend who had made it for a customer. All turned out well execpt for the bumble bees which were killed by the temp. Can't remember the kind of wood. Yes I can - it was barn wood. Probably pine.

[scsmith42]

I've sterilized several items for folks.  Usually the finish is ok, but most non-sterile lumber was air dried and then crafted into a project when the MC% was above 10%.

Sterilization runs tend to cause the lumber to dry further and move a bit.

YMMV.

Scott

[Brad_bb]

The only bug I'm aware of that will be in dry wood is PPB.  She was grossed out by those tiny things?  Is she away how much bugs she eats every year in flour, cereal and other foods?  Besides they were in the wood not on the surface.  

...And how did Yellowhammer show carcasses if they are in the wood?  Presumably they would stay in there unless they had a dramatic death scene where they fall halfway out of the frass hole and rive in death throws before succumbing and have "X"s over their eyelids and tongues hanging out.
Tom's death scene

But seriously, once whatever is in the wood emerges as adults, that should be the end of it.  If it's only here and there, not that big a deal.  If it was highly infested, that's another story.  But having a finish the table should not be re-infested.

[YellowHammer]

I haven't seen Tom and Jerry for awhile, but that was a cool clip.  I loved it.

To answer the question, yes, PPB's can re-infest wood, and yes, I will dig into my wood with a knife and magnifying glass to prove to myself and my customers that I'm not selling bug infested wood.

Let's cover the life cycle of the several varieties of Powder Post Beetles...They are quite selective and generally hardwood PPB's don't infest softwood, and softwood PPB's don't infest hardwood.  That's one reason I used soft wood for my pallets that I dry hardwood on.

However, they do re-infest wood in a continuation of their life cycle, it wouldn't make much sense if they didn't, why would they find a good feeding and breeding source and then leave it?  So PPP's can stay dormant for as long as 7 years, although many of the calls I get are for wood that is under 3 years after purchase from "other sources."  Do you know what happens if you kiln dry or air dry wood and don't get it to the magic sterilization temperatures?  Thirsty bugs.

Either way, nature finds a way, and as they mature to beetles have a behavior, if possible, to drop a load of eggs on the best wood available, the surface of the tunnel that Momma just bored through.  So the larvae hatch, and crawl back down the tunnel and reinfest the wood.  They are called Powder Post Beetles for a reason, they will reinfest and reinfest barn and basement posts until they eventually turn them to powder.  Of course, new ones will fly in to the food as well.  The life cycle continues.  

Pesticides only go surface deep, so must create a barrier, like a termite bond on the dirt around a house, and will kill the insects as they emerge and pass through it.  However, pesticides like Timber kill by desiccation, so isn't instant contact kill.  Boracare is better but still kills generally by the same mechanism.  Pesticides, even the gold standard for PPB's only goes about an eighth to 1/4" inch deep, and doesn't do anything to kill the larvae in the wood.  If you don't believe me, read the label on the product.  It says it clearly.  I had to prove it to a builder who had just installed an entire reclaimed beam structure in a house, and was assured by the seller of the wood that all the bugs were dead simply because they had been sprayed.  However, he talked to someone who said he may have screwed up.  So he came by the shop to ask me and I said, yes, you may have screwed up.  Then I said, nope, he didn't have to believe me, it said so right on the label.  I Googled it real time for him, printed the pesticide label disclaimer out, handed it to him and said go find a lawyer, you might need one.  So if you have a 6 x 6 of reclaimed barn wood with PPB's in it, the pesticide is not reaching the majority of the wood.  So the little guys just keep doing what they do, happy and hungry inside. So tell the wife, significant other or customer that the reclaimed beams or furniture you want to install in the house may have an entire ecosystem of bugs inside, but don't worry, they will die a little while after they emerge and fly around the house a little. The finish may get them as well.  No big deal.  That's why the wife freaked.  No amount of assurances by me or hubby were going to make her feel less than grossed out.  

A couple of humorous, to me, examples, besides the vanilla one I already told.  One was experienced by a former Forum member and it forced him to re evaluate his business model and invest in a kiln.  He cut, air dried, finished and installed a maple countertop for a lady, got paid, and forgot about it for a couple years.  Later, while she was eating a pizza, she saw some frass on the countertop and the floor.  PPB's were emerging from the finished and installed countertop.  Being a good guy and a professional, he went to her house and first hand eyeballed what was going on to prove it to himself, had a little freak out when he got home, then pulled up the counter and replaced it with a temporary plywood one.  Then he replaced it with professionally kiln dried and sterilized wood at no cost to her and then bought an L53 kiln, and would never sell unsterilized wood again.  Ever.  No cost to her, but lots of cost and lost reputation to him.    

Another cool example was a guy who called me up on a Sunday with a freaking out wife (he was freaking also) because he had built a headboard of "not my wood", and as they woke up in bed, they noticed that the occasional bug was emerging out of the wood and crawling around in his wife's hair.  Yeah, that caused a freakout.  He had built the headboard about a year prior, and it was fully finished and had been in his house during that time.  He admitted he bought it from a Craigslister who told him sterilization of wood was unnecessary.  He calmed his wife, got her out of the house, (told her to go shopping), ripped the headboard off the bed, pulled everything outside and did some web surfing, found me, and asked me what to do about it.  That was a sure nuff "burn it" comment from me.  It was hard for me not to laugh, but I did get in a "should have bought my wood."

Of a more serious nature, a person called and asked if wood taken from their grandfather's barn, turned into a table, and placed on the hardwood floor, could have somehow been infected with bugs that traveled down the table legs and into the floor? I said sure, why do you think that's happening?  They said that's what the entomologist told their insurance company, as they filed an insurance claim because they had to rip up their hardwood floor that the table was sitting on for years.  I don't know if they were PPB's but they were bugs, and bugs is bad, and bugs can live in unsterilized wood.  Another "not my customer and not my wood," thankfully.

Anyway, those are just a few example, I have lots more.

Oh, I didn't cover the comment about the X's in the eyes of the kiln dried and sterilized bugs.  Yes, I do inspect my sterilized wood, and yes I do go prospecting for them.  How else can I see if what is happening is really happening?  Take someone else's word for it?  Nope! You can't believe the stuff on the internet anyway, we all know that.  I want first hand, eyeball proof.  I enjoy seeing the X's in their eyes.  Want to see a couple photos?  The first one is not uncommon to see, and one of my favorites.  This was some many month air dried red oak that I had removed from my kiln.  Can you imagine what was going through this little guy's head as the wood got hot and he bored out to safety only to hit the hotter air in the kiln and flash off in a puff of smoke?  If a bug could scream, I bet it did.  All that was left was a hollow exoskeleton.  





The next picture was of some old and reclaimed wood that I bought from a guy who dismantles old buildings for Jack Daniels under contact.  This board was from a couple packs form Unit 6, old as the hills, and was shot full of PPB holes.  Of course it was, it was old reclaimed barn and building wood, and despite my better judgment, I bought the two packs of it.  So I sterilized it, got a bad feeling, and then sterilized it again.  I got the wood so hot that I left melted sticker tracks in the red barn paint.  Then to make sure I had killed everything, I planed some of it, and then went "bug hunting" with an Exacto knife and magnifying glasses.  Guess what I found and was able to dig out?  A bunch of little charbroiled bugs about the size of the lead in a pencil and had little X's in their eyes, just like Tom in the cartoon. If you look close at the photo, you can see the actual X's in their eyes.  They look like classic PPB's remains to me.  I was happy that the sterilization works, and I was unhappy that the proof was so clear.  So going with my better judgment this time, even though I was confident the bugs were dead, I took both packs to the burn pile with a forklift and tossed them in.  Woosh, the wood was gone, the money was gone, and so was any chance of someone suing me if they found the bugs, even of they were dead, in wood that I sold.



 

Speaking of that, I have been threatened with lawsuits (more than one) because people have found holes in my wood, and wrongly assumed the bugs that made them were still alive.  That's why we keep detailed records of every load I dry and sterilize.  That's also why we never, never sell lumber with PPB holes in them, and also one of the reasons we always plane ou wood before we sell it.  

Look, people can believe what they want, do what they want, and sell the wood that they want.  Not my problem.  However, I do know that one of my repeat customers is a professional bug exterminator, and he loves insurance claims that originate from Craigslist Air Dried Wood.  He makes lots of money off them.  Occasionally, in order to satisfy the insurance company, he has to "tent and fumigate" the house, to the tune of $25K a pop. Of course, then the insurance company goes after the poor schmuck who sold the wood to the homeowner, if they can find them.  Bad day for the "wood guy."  It's the only way, he as a professional bug exterminator, will sign off that bug remediation has been successful, besides heat.

The realtity of the situation is that bugs leave holes, not just PPB's. Bugs and bug holes freak out the customers.  Yellowhammerism --- Bugs is bugs and bugs is bad.  I don't sell bug wood, and I don't fix it in other peoples' wood.              

[Walnut Beast]

Excellent stories and information!!

[Old Greenhorn]

An epic and definitive post Robert, Thank you.

[Walnut Beast]

Another good read!

https://extension.psu.edu/powderpost-beetles/

[Walnut Beast]

I have a customer with a 6 year old walnut table that is showing signs of powder post beetles. They want to try and use my nyle l200m to kill the bugs. It is 7 boards glued together for a top and has a matte poly on it as well. I was thinking of putting it in the kiln at the end of drying some white pine when I am setting the pitch. Would 160 degrees ruin the table? Glue or finish?

Would just doing 130 degrees for 24 hours be a better bet?

How likely are we to trash this table?

Just curious if there is any sap wood in the table or all heartwood ?  

[YellowHammer]

Thanks OG, and excellent reference WB.

The key points I was trying to make in my extended commentary is that bugs eat wood and that's what they do.  Heat kills them.  Air drying, kiln drying at low temps, and most other things don't.  Insecticides are of limited value and come with caveats.  Bugs and bug holes in wood are considered radioactive by most retail customers.  Most people react badly to the thought or possibility of live bugs in their wood, in their house.

As a business, any operator who takes on bug extermination should be prepared for the possible legal consequences if they are not successful.  Sometimes, as a kiln operator, you just have to say "No, I don't do that."

Bugs is bugs and bugs is bad.  I don't sell bug wood and don't fix it in other people's wood.  I'm not going to get tangled up in their mess.

 

[Don P]

Just curious if there is any sap wood in the table or all heartwood ?  

They much prefer sapwood but mine aren't high class, they don't kick heartwood to the curb.

[GeneWengert-WoodDoc]

Clarification... for the lyctid PPB, which gets into dry hardwoods, The time from when the eggs are laid until the insect hatch's can be as short as 10 months in a warm climate.  Twelve months is more common.  However, in a cold climate without much warming, the life cycle can extend to two or three years.

The ambrosia PPB likes wet wood and likes hardwoods and softwoods.  

If you find an insect, the PPB has antennas that have a small enlargement or club looking feature at the end of the antennas.

[Peter Drouin]

So YH, How do you know the wood is right when you buy kd wood from other mills to resell?

[Peter Drouin]

I sell only green wood. How can someone come back and sue me? I would think the buyer would take all the risk.
 They know it's green, with all the things that can go wrong with it.

[Southside]

Had a customer who asked me to T+G some Pecan that had been on stickers in a barn for years.  This was going into a kitchen remodel as part of a whole house remodel, and just the HVAC budget was over $75K, so they were spending coin.  I took a look at the wood and it was full of PPB holes and frass as expected.  

When it came time to do the job I had a load of wood in the kiln and told them it would be a couple of weeks by the time that load was out and I could get theirs in, oh no - has to be done right now, yesterday even, can't wait for no stinking kiln time, they had a bug guy who said he could spray something on it for them, after it was down.  Last I knew their plan was to T+G it in their workshop and lay it down as is.  Not touching that with a 10 mile pole.  

[YellowHammer]

So YH, How do you know the wood is right when you buy kd wood from other mills to resell?

This is one of the "gates" that anybody who supplies to us must pass, i.e. proof of sterilization.  I will not trust a Craigslist or Facebook supplier and will not buy their KD wood unless it meets our standards for quality (It almost never does) but if it does, they either must give me proof of sterilization (never do) or I only pay green wood prices for their supposedly KD wood, because I will have to resticker and kiln dry the wood myself.  Proof of sterilization is simple, I tell them to take a dated time stamped photo (any cell phone will time stamp and dates photos) of the load and kiln controller at the beginning of a 150F sterilization cycle and then again at the end of it, at least 24 hours later.  Simple, two photos.  NOBODY will do this.  All I get back is "The wood is kiln dried so it is sterilized" which is a big "No it isn't." from me.  Of course it'll depends on the kiln type, the cycle, and the operating temps, some do ands some don't, and it doesn't help them since I know pretty much every commercial kiln operator in this area, so I know when they are "mistaken."  Then they say "Well the kiln manufacturer says it does" and then I say "Which one, I know them, too." and then they ask what I will pay and I say green wood price because I have to sticker, dry and sterilize it.  Then we cut a deal or they walk away and sell the unsterilized wood to some unsuspecting person.

As an example, the guy I bought the reclaimed wood said that since the wood was so old, there were not any bugs left in it, although it was shot with holes.  I think he honestly believed that, or was just so used to telling the lie, he sounded like he believed it.  I said "no" and asked him to call me back after the wood was sterilized if he really wanted to know, and guess what, he never did (not surprising) and just keeps telling people the wrong thing.  I have him on call block now, I don't even want to get his phone calls, he's a crook in my book.

Any other wood I buy and sell comes from true professional kilns, who always have kiln certifications and processes in place.  They don't play and that's one reason I like dealing with them.  I know what I'm buying, and more importantly, I know what I'm selling.

I sell only green wood. How can someone come back and sue me? I would think the buyer would take all the risk.
They know it's green, with all the things that can go wrong with it.

They most likely can't sue successfully on green wood, especially if you have a disclaimer on the reciept you give them, a "Sold as Green Wood" statement.  However, expecting the average person to know all the things that can go wrong with green wood is not always the case.  Some people I talk with have full knowledge and know exactly what they are buying, and some not so much.  It's one of the reason I don't sell green wood fire place mantles.  I know where that piece of wood is going, and I know it's certainly going to crack and may have bugs and could be bad.  

I talk to lots of people who become our customers because they have bought green wood pieces (from others) in the past and "had no idea" what could happen, and just as many so called experienced woodworkers who buy green or air dried lumber and stack it in their wood shop to dry and come back a while later and see frass in all their lumber stockpile, even their KD stacks bought from Home Depot.  I hear about it because they are calling me to freak out and ask how bad it is.  I say, well, it's not good.

I'll tell you another pet peeve I've got (one of many), it's those "Barnwood Builder" shows on TV where they put reclaimed Barnwood in homes. They skip the whole fumigation and sterilization step on TV.  It trickles down to the average person who buys "reclaimed wood" other places and thinks the wood is safe, "as is".  I had one of those during the summer.  A person came in and told me they had already put a bunch of reclaimed barn timbers in their home and then started reading up on it after being "warned" by their friends about bugs and mold, (in their case they were seeing mold on the timbers, his family was starting to have reactions, and he was suspicious of the wood being the cause) and became concerned.  So they called me out of the blue after getting "vague" answers back from the individual they bought the timbers from, who said "the timbers were fumigated" and so I told them I knew most of the licensed fumigators in my area and if it was done right, they wouldn't have to worry about it.  However, they said "he did it" and now it sounded like this one was going to get bad, and it was something I definitely didn't want to get involved in. Another "not my wood, not my problem" situation and I told them that.  They called me back later and were upset, because upon further questioning, his fumigation technique was to throw a tarp over the reclaimed timbers out in the yard and put a Wal Mart can of bug bomb under the tarp.
Yep, that is all he did.  When they pushed him about a warranty, he said something to the effect of "Hey, I'm a little guy, I never said the wood was sterilized, only that I had fumigated it."  

I think the bottom line is that anyone selling wood of any condition, green, air dried, kiln dried, etc should just be honest and upfront and educate people as they sell the wood.  It's the dishonest folks lying and peddling "radioactive wood" that affects everyone.
 
By the way, in my insurance coverage, I am covered for "End user mold and insect damage".