How to treat worms in walnut?

[tibi]

Hello,

Yesterday, I bought 80 mm thick walnut slabs for my new workbench. It has been air-dried for 10+ years. I was warned that there are wormholes in the sapwood, but for the price of 150 € for the whole lot, it was still a bargain.

I cut off the waney edges and most of the wormholes, and here is the result

My question is how to destroy any existing worms or their larvae. I have seen only a single one when cutting - it was of this type below. I do not want to move the wood to my workshop before making sure that they will not attack my other wood or the building itself.

This is the product that I can buy in Slovakia : Plus I

Is applying such products safe before processing the wood? (cutting, planing, sanding, etc.). I do not want to risk health hazards by breathing fine dust with such chemicals.

Thank you.

 

[recipio]

If you don't mind cutting the wood put it in a deep chest freezer for a week or two. That will destroy anything.

 

[tibi]

If you don't mind cutting the wood put it in a deep chest freezer for a week or two. That will destroy anything.

Thanks, but I do not have such a freezer (and if I had one, it would definitely not be empty). I need 2 boards of 1,8m slabs for the workbench top, so I cannot cut it into smaller pieces.

 

[kgill]

Where, may I ask did you buy it?? And can I get some?

 

[tibi]

Where, may I ask did you buy it?? And can I get some?

It was bought in Slovakia from an old pensioner, who had it air-dried for more than 10 years. It is from his own garden, but the bark was not removed properly, which might be why the woodworm attacked it. The street price for rough saw walnut in eastern Slovakia is around 1300 € / cubic meter.

 

[MikeK]

The street price for rough saw walnut in eastern Slovakia is around 1300 € / cubic meter.

That's a bargain if the wood is in good condition! The price for kiln-dried and steamed American black walnut here is between 3,200 € and 3,900 € per cubic meter, depending on the slab thickness (35mm to 65mm). The price for European kiln-dried walnut varies between 3,100 € and €4,200 € per cubic meter, depending on the slab thickness.

 

[tibi]

That's a bargain if the wood is in good condition! The price for kiln-dried and steamed American black walnut here is between 3,200 € and 3,900 € per cubic meter, depending on the slab thickness (35mm to 65mm). The price for European kiln-dried walnut varies between 3,100 € and €4,200 € per cubic meter, depending on the slab thickness.

Yes, it is much cheaper than in Germany. Are the prices for rough sawn walnut or planed? Here in Slovakia, there might be only a few sawmills that offer planing. Every woodworker does it himself.

I am now cutting my walnut into rough dimensions and it still has some wormholes here and there. The issue is that the worms are not yet advanced enough to bore holes perpendicular to the show face, so I have some holes that look like a tunnel in longitudal cross section. I have never used epoxy, but I think that this is the first time I will find it useful.

 

[Jacob]

A hole in the surface is a good sign in that it means a beetle has departed!
If still alive some are due to emerge quite soon as the weather warms up.
I'd just carry on and make your bench and perhaps give it a dose of treatment when it's finished. They can take several years to emerge but not likely to attack very dry wood indoors.

 

[tibi]

A hole in the surface is a good sign in that it means a beetle has departed!
If still alive some are due to emerge quite soon as the weather warms up.
I'd just carry on and make your bench and perhaps give it a dose of treatment when it's finished. They can take several years to emerge but not likely to attack very dry wood indoors.

I will see if some piles of wood dust will be around the bench. All my indoor wood (except the woodshop itself) has a moisture content below 6 % (minimum what my moisture meter is able to read). The walnut has moisture below 15%, as it has been air-dried. Mostly around 10-12%.

 

[Fitzroy]

I like Barrettine products, this one is for woodworm eradication. It contains permethrin which is the same stuff as is on insect nets. It can't be super deadly for humans as it is prescribed for some mite conditions as a cream/medicine. However, not sure I'd want to breath wood dust impregnated with it, but then again I'd not want to breath wood dust full stop. I think i'd be in the Jacob camp and give the finished item a coat rather than the raw timber.

 

[tibi]

I like Barrettine products, this one is for woodworm eradication. It contains permethrin which is the same stuff as is on insect nets. It can't be super deadly for humans as it is prescribed for some mite conditions as a cream/medicine. However, not sure I'd want to breath wood dust impregnated with it, but then again I'd not want to breath wood dust full stop. I think i'd be in the Jacob camp and give the finished item a coat rather than the raw timber.

Thanks. I will do it this way and apply the product before applying the final finish.

 

[MikeK]

Yes, it is much cheaper than in Germany. Are the prices for rough sawn walnut or planed? Here in Slovakia, there might be only a few sawmills that offer planing. Every woodworker does it himself.

Rough sawn slabs as they came from the mill.

 

[XTiffy]

Most wood worm killers are an insectiside in suspension of a light oil for penetration. Paraffin (Kerosene) alone will penetrate and kill any larve. If you have flight/exit holes use a hypodermic ( Equine Vets use large ones, which are ideal) to inject into the holes. These large hypodermic & needles are great also for injecting hot water into joints of chairs etc. to dismntle, if glued with animal glues. Apart from Xray there is no way to know what bugs are eating your timber.
Your grub is too big to be woodworm, so should be pretty obvious when exiting.

 

[Richard_C]

A permethrin based product might be useful. It's used in fly sprays, anti-lice shampoo etc. and is generally rated safe for human contact. Toxic to insects and aquatic life because they can't metabolise it. I think it's bad for cats, but dogs are OK. A few people get skin sensitivity. As far as I recall (no guarantees here) permethrin group compounds are not photo stable, daylight breaks them down. That makes it pretty good for timber treatment because any surface residue becomes inactive (much like fly spray, you need to spray again after a while) but that which goes into the timber keeps it's activity much longer. I would treat the finished item and repeat every 3 months or so for a couple of years to kill any emerging bugs over 2 life cycles. It's a long time since I "did the science" around using it but it made a major difference to human health when it was discovered, I think we just had DDT and chlorine compounds before that.