worms or termites???

[Peter Scoma]

I'm looking to make a massive roubo for my shop and struck a bit of luck when an ad came up on CL for some 100 yr old, hand hewn oak beams the seller was getting rid of for 5bucks a LF. The beams were stored inside a barn adjacent to a farmhouse (pre civil war). It was dark in the barn and while I picked the beams out with a flashlight I failed to notice the small 1/32-1/16in holes covering the majority of the pieces until I got home and unloaded them. The beams are about 8in by 14in and appear structurally sound but I'm uncertain whether the holes are wormholes or termites. I have yet to mill them up so I do not know how deep the holes are but I'm concerned I made a foul-up and purchased termite ridden beams.

Is there any way to differentiate wormholes vs termite holes? Is the wood still usable if they are non-active termite holes?

Ill try and post some pics for your review.

Thanks in advance for any replies.

PJS

[Jim Matthews]

Were it termites, you would have found the boards light, and powdery.

The worms have likely come and gone.

If you're genuinely worried about an infestation, bag and fumigate, first.

[ken gibbs]

In air dried wood, you will find 1/16th " worm holes. You can kill them using any good insecticide by overspraying the holes. I recently added a sugar maple top to my kitchen counters and nine months later I found tiny little piles of sawdust on top through five layers of urethane. Don't sweat It. I air dried this sugar maple outside. You can charge extra for the worm holes if you are selling this oak. You will have to spray several times over a four week period to kill them.

[David Helm]

What you likely have are wood boring beetles (lyctids) commonly called powder post beetles. Bang on the wood, if you get powdery sawdust falling out it is an active infestation. Common pesticides won't kill them. Since their lifecycle is fairly long it takes a while to get them all. Keep this wood away from any other hardwoods you have as hardwoods are their food of choice. If the infestation is large, you may not have much solid wood left in the plank. Incidentally, the culprits are the larvae of this insect. They travel around inside the wood eating till maturity, then exit, via the little holes you see to continue the cycle. Just so you know, I'm not guessing. I am a licensed structural pest inspector.

[David Helm]

Why don't you post some pictures?

[Ed Labadie]

I've used Timbor on Powder Post Beetles with excellent results. Make sure you saturate the wood several times with it.

http://store.doyourownpestcontrol.com/search.aspx?criteria=timbor

Ed

[Scott T Smith]

I concur with David - it sounds like PPB. If they are still active, fuming with ammonia will kill them too.

[Danny Hamsley]

Sometimes ambrosia beetles infest a dying or dead oak. They bore about the same sized hole as the powderpost beetles, but the hole has a small black ring around the outside circumference. It is distinctive. It adds character and does not really degrade the wood. They only attack green dying trees or freshly cut logs. You can tell the difference between them and the PPB's (powderpost beetles) by the black color of the hole and immediate surrounding wood and the absence of the fine wood dust or powder that is associated with the dreaded PPB's. Plus, the scourgy PPB's only infest dry wood, unlike the ambrosia beetles.

I hate PPB's. Did I say that I hate PPB's?????????? If you have them, that is a shame.

[Peter Scoma]

Sounds like PPB are the likely culprit but I've attached some pics for your review. I hand planed the top of one beam last night and it seems as though the holes are mostly limited to the sapwood. After I planed I went over the surface with a wire brush and the holes and channels are definitely full of brown powder so i'm assuming the infestation is active based on the above posters information.

I'm considering some of the procedures suggested but want to ask if it is ok, preferred, not good, etc. to treat the wood after it has been roughsawn. Is it necessary to treat the lumber in its natural form or does it not really matter. The beams will be milled down to 6x6, 6x3 and 4x4 pieces so I'm hoping the heartwood isn't as affected.

Check out the pics below and let me know what you think.

Also, the beams are very heavy, especially for being as dry as they are. There does not appear to be any structural compromise to the material but I'll find out more tomorrow AM when I start cutting into this stuff. For now, its on the other side of my shop in isolation.

Thanks again for the replies,

PJS

[David Helm]

Definitely appears to be Lyctids. I would go ahead and mill, then treat the pieces. Burn all scrap.

[Peter Scoma]

Definitely appears to be Lyctids. I would go ahead and mill, then treat the pieces. Burn all scrap.

Thanks for your help David.

Would you concur with Ed's recommendation of using Timbor to treat the wood after it has been milled?
Thanks
Peter

[ken gibbs]

Contrary to an earlier post, common household insecticides and mitacides will kill powder post beatles. The problem is getting the liquid insecticide down to the beatle larve. Air dried wood and especially hardwoods will always be exposed to powder post beatle infestations unless you can completely isolate your wood stocks. You can also charge more for furniture that shows PPB faults. Just over spray several times.

[Scott T Smith]

Timbor will work, but personally I typically only use it on green wood, as I dislike rewetting already dried wood. Timbor works best on green wood also because the moisture in the wood helps to wick the borate through the cells.

Personally, I would go the ammonia fuming route.

[Don Buck]

In lieu of chemical treatment, I would recommend that you heat treat your remanufactured lumber. Heat treating the wood to a temperature of 140 degrees for a few hours will kill lyctid in all life stages. The lengths of time at 140 degrees F is dependent upon the moisture content of the lumber and the thickness of the boards. Typically 3 hours at 140 degrees will suffice for 4/4 lumber and times up to 7 hours would be required for 12/4 (assuming the MC of the lumber is approximately 14%). It certainly wouldn't hurt to just heat the boards overnight to make sure they get scourched. You can contact your State Department of Agriculture - Animal and Plant Health Inspection Services (APHIS) or the USDA PPQ office to get a list of heat treating companies who can provide the service. Typically the service will be offered by lumber dry kilns or pallet manufactures who heat treat pallets for export. Often your land grant university can provide a list of heat treating service providers.

FYI - I've read that lyctid larva typically favor sapwood and are typically found in hardwood that is 5 years old or less in age (5 years since dried to 15% MC or less).

[Scott T Smith]

In lieu of chemical treatment, I would recommend that you heat treat your remanufactured lumber. Heat treating the wood to a temperature of 140 degrees for a few hours will kill lyctid in all life stages. The lengths of time at 140 degrees F is dependent upon the moisture content of the lumber and the thickness of the boards. Typically 3 hours at 140 degrees will suffice for 4/4 lumber and times up to 7 hours would be required for 12/4 (assuming the MC of the lumber is approximately 14%). It certainly wouldn't hurt to just heat the boards overnight to make sure they get scourched. You can contact your State Department of Agriculture - Animal and Plant Health Inspection Services (APHIS) or the USDA PPQ office to get a list of heat treating companies who can provide the service. Typically the service will be offered by lumber dry kilns or pallet manufactures who heat treat pallets for export. Often your land grant university can provide a list of heat treating service providers.

FYI - I've read that lyctid larva typically favor sapwood and are typically found in hardwood that is 5 years old or less in age (5 years since dried to 15% MC or less).

Don brings up a very good point regarding heat sterilation; as old as your beams are they should have reached an EMC of about 12%, or thereabouts, unless it was very humid where they were stored.

You might be able to find a kiln operator near you that can slip your milled planks into their kiln during a sterilization cycle. For a list of kiln operators, check on Woodweb or Forestryforum.

[Danny Hamsley]

Typically the surefire way to treat for PPB's is to heat the wood to an internal temperature of 130 for 4 or more hours. I know that is hard to do. Fumigation is also supposed to work. Treating with a borate spray like timbor may not penetrate deeply enough to kill eggs unless you can build a vat and really let the beams soak for a good long time. Then, they have to re-dry.