That's sounds like a awesome slab. It's not very often we get a chance at wood that big air dried
I would cut it up and build a dresser or something.
I can't offer any advice on the bugs. When I have wood with bugs I get rid of it.
But that slabs sounds spectacular. So I would figure something out. I don't like the kiln idea it changes the wood that makes handtool work more difficult.
Good Luck

 

Yup, powder post beetles. You don't need to watch for more holes to show up, the beetles will push their fine sawdust powder out the existing holes. It will take a while so you'll need to wait.

I inherited a cabinet that had powder post beetles. The local pest control guys sprayed it with borate (ie: BoraCare). That didn't really help. The other pesticide option was to gas it. The outfit that does that around here told me I'd have to get a shipping container to hold the furniture and gas and put it somewhere no one could get at it for three days. We tossed it instead.

If the bugs are active I'd certainly look into a kiln. If your other choice is to throw the slab away, what do you have to lose?

 

had a mrytlewood slab that had PPB infestattion in the sap wood,and it was an old slab 30+ years.i went ahead and made a live edge table with it for my brother.he told after a little while some dust showed up.he kept the table and i guess they finally died because the dust stopped showing up.not as many holes as yours though.id maybe wait a few weeks and see if there is anymore activity.

 

Yes they could spread to other wood if conditions are right. Cold doesn't seem to kill them but heat does so a kiln would work or you could try sealing it in clear plastic and put it in the sun when the weather gets warmer. It needs to get to at least 140+ degrees for several hours so check it with a thermometer.

If it is currently in a cold building you will want to put it some place warm to reactivate any dormant bugs still in the wood in order to see more saw dust from them.

A piece that thick is hard to get borate to penetrate so the best insecticide process would be fumigation. Do you know anyone who is having their house fumigated for pests? You could put the wood in the house.

 

Probably powderpost beetles, but there are some longhorn beetles (roundheaded borers) that cause similar damage, but they're less common. Powderpost beetles can be killed with boric acid, like the stuff you use for roaches, or other borate compounds. Apparently you can kill them with heat, but I'm not sure how hot you have to get them.

 

Yes they could spread to other wood if conditions are right. Cold doesn t seem to kill them but heat does so a kiln would work or you could try sealing it in clear plastic and put it in the sun when the weather gets warmer. It needs to get to at least 140+ degrees for several hours so check it with a thermometer.

If it is currently in a cold building you will want to put it some place warm to reactivate any dormant bugs still in the wood in order to see more saw dust from them.

A piece that thick is hard to get borate to penetrate so the best insecticide process would be fumigation. Do you know anyone who is having their house fumigated for pests? You could put the wood in the house.

- LesB

Cold will kill them similar to the pine beetles we have up here but it needs to be -40 or so for two to three weeks. There are benefits to being in Canada!

 

I really doubt that it set in a garage for 40 years and just NOW got infested. I'm betting it's older damage. For now clean it really well and get all the dust off of it. You can always contact a local pest control and have them come take a look. It's not a case of once active forever active. If you don't wanna get a chemical fix you can call some lumber yards or sawmills and try to find a kiln. Perhaps a green house might be able to help too

 

+1 I won't use lumber with bug holes; unless it has been recently kiln dried by a trusted source.

Surface chemical treatments will not kill the hibernating larva, only bugs once they emerge. Pesticide gas treatments sort of work, but are most expensive. Heat is easy way to kill bugs in wood.

General recommendation for up to 2" thick lumber is three to five hours above 140˚ F for bug sterilization.
With a 130˚ F kiln temperature, sterilization will take 10 to 12 hours. Allow more time for thicker lumber.

It doesn't take much to make a hot box from foam slab, construction adhesive, and small fan driven heater; but it is easier to find a local sawyer with kiln and have them include your slab on the next "bug kill cycle".

Best Luck.

 

I really doubt that it set in a garage for 40 years and just NOW got infested. I'm betting it's older damage. For now clean it really well and get all the dust off of it. You can always contact a local pest control and have them come take a look. It's not a case of once active forever active. If you don't wanna get a chemical fix you can call some lumber yards or sawmills and try to find a kiln. Perhaps a green house might be able to help too

- JCamp

disagree the slab i had was well over 30 years old when the beetles infested it.my dad had about 30-40 slabs an old logger gave him that were cut 30-40 years earlier before the beetles got into the sap wood.

 

Wow thank you all for the quick response. I really appreciate all the info and ideas.

Based on my timeline I'm going to play it safe. I found a mill with a kiln that can help. They run a 16 day cycle and offered to add my slab in at the beginning or end of the cycle just to kill anything.

My mind was made up when they offered to run it through the huge planer for a couple bucks more while it's there.

Having second thoughts about cutting this thing up. How to convince my wife we need a basement bar instead of finishing the kitchen?

 

Probably would consider the chemicals more if it wasn't going in the kitchen.

I appreciate using hand tools and I'm trying to incorporate them more but don't plan to on this project. How does the kiln change the wood? Is it harder due to the lower moisture content?