Non-toxic woodworm treatment?

[mahoak]

A while back I bought a slab of spalted beech with live edge to use for making a bathroom worktop. I started the other day to cut it and noticed that it has quite a few woodworm holes on it. underneath where it had been resting flat for a while were only couple of areas with fras so I assume that most of the infestation has gone. However to be on the safe side I am thinking of treating the wood before either fnishing it with varnish or wax.

Can anyone recommend any woodworm treatment that is non toxic and doesnt contain Permethrin or Cypermethrin (or any kind of dangerous chemical like that) please?

[Job and Knock]

First thing I'll say is that beech is a completely unsuitable species for use anywhere there is an elevated moisture content - the timber is not regarded as durable in such circumstances. In fact what happens to beech is that it turns black over time. The worst example I've seen of this was a sports centre built in the 1990s which we worked on when it was about 10 years old; despite the interior door casings and window frames having been given three coats of commercial lacquer when new at ten years of age we needed to rip out and replace a lot of them (especially in the vicinity of the sauna) because they'd gone black in large areas. A prime example of a so-called professional (architect) not heeding the notes in many books on timber species

If you are dealing with spalted timber you may actually have two problems. The first is wood borer infestation, for which the only cures AFAIK are either toxic (e.g. pemethrin, etc) or difficult to arrange (e.g. irradiation, microwave treatment, etc); the other issue is the fungus itself which is what causes the spalting in the first place (and is often introduced into the timber by the wood borers or bark tunelling species such as the ambrosia beetle). This fungus is a known respiratory irritant and can cause severe inflamation of the nasal tract if inhaled whilst doing things like sanding, sawing, etc. It is a known issue for wood turners and can only be dealt with by using extremely good dust masks (i.e. FFP3) and source point vacuum extraction (class M or higher) of sanders, saws, etc.

If you are unwilling/unable to treat conventionally about the only thing I can suggest is that you mask up and machine the timber, and then sand as required. Then coat the surfaces liberally with a wood hardener such as Bonda-Voss Wood Hardener. Two coats should do the job followed by a sanding then 3 to 4 coats of a durable sealing finish such as a lacquer (NOT oil or wax). This should fill any remaining flight (exit) holes. The wood hardener will plasticise and waterproof the surfaces of the timber, hardening the surface so that any wood borers remaining in the timber simply cannot bore to the surface - the lacquer finish seals any cracks, fissures or pre-existing flight holes. This is obviously not a 100% certain treatment - for that toxins would be required.

I cannot emphasise strongly enough the negative effects of breathing sawing or sanding dust from spalted timbers. In my case I have become sufficiently sensitised that even a few breaths causes my nostrils to completely close and for me to have breathing difficulties for several hours afterwards. It is a highly unpleasant thing to live through and even the use of anti-histamines has little effect. Thios was not caused by excessive exposure to the spalted timber, either. I've dealt with relatively little spalted timber in my working life. I also know a trade wood turner who similarly cannot work with the stuff any more for the same reasons. So you have been warned

[mahoak]

Oh dear... there's me thinking that it would be an easy job. Thank you for the advice J&K. As it happens I do have a Metabo sander which is attached to a nice Metabo extractor with M class filters. And I have a decent face mask as well (I think). The wood does not need a lot of sanding because it is quite flat and smooth and I rather like the rustic look.

Unfortunately I dont have the option of giving up using the wood because I paid £100 for it and it would be a shame to waste it. The slab measured 200cm x 65cm x 5.5cm.

The reason why I was asking for non toxic treatments was because I read some articles online that warned regarding the effect of using such treatments can have on the brain and health? Is it really that bad?

I take on board your suggestion though and it sounds good to me. Which leads me to ask: any particular brands of wood hardener better than others? And what brand lacquer would you suggest?

Here's a picture of the timber:


And a picture of the face mask (JSP Force8):

[mahoak]

By the way I may have got it wrong in regards to what type of timber it is and after looking at pictures on internet I think it may be birch and not beech. Although not sure if birch can grow to that girth size

[Job and Knock]

The reason why I was asking for non toxic treatments was because I read some articles online that warned regarding the effect of using such treatments can have on the brain and health? Is it really that bad?

Well, the odd thing is that pemethrin is actually used to treat scabies and lice (any comments about that on-line?). Like everything else in this world it depends on the level of exposure. Read what you like into that, but before condemning any wood treatment based on anything you find on the net I'd suggest maybe getting hold of the COSHH sheets for any compound you are likely to use and having a good read.

There's also the issue of protection - so when working with any form of chemical treatment it's always best to wear a P3 mask, ideally with active carbon filters, eye protection and appropriate gloves (nitrile). The Force 8 mask you have is a very good mask and can be self-checked for face-fit. I'd certainly go with the gloves for pemethrin, but maybe not the goggles (but then again I wear spectacles)

Personally I'd just go with pemethrin to treat the timber (making sure I worked out of contact with/reach of kids and pets), but still thoroughly seal the wood afterwards with 3 or 4 coats of finish (all surfaces, including the back). I take on board your concerns, but at the end of the day the only way to effectively kill insects in timber is to use an insecticide..... I'd also like to see scientific proofs for these claims abuot pemethrin (I'm saying that because there are a lot of people out there who will make unfounded claims about anything - remember MMA?)

Which leads me to ask: any particular brands of wood hardener better than others?

I did state the brand, I thought (Bonda-Voss Wood Hardener - just sold as Bonda brand these days. My local builders merchants stocks it). That's one I've used and AFAIK it's still one of the approved products for heritage work on C of E properties (at least that's where I've used it in the past). I know that there are others (often cheaper), but I've found one which works well so why look for a cheaper, unproven alternative? One thing I will say is to get several cheap brushes to apply it - being a polyurethane it just destroys any and all application tools. I would wear gloves to apply that, too, because PU will turn your skin black for a few days (until the old dead skin at the surface flakes away). If nothing else using a wood hardener will make your timber a lot more waterproof which isn't a bad idea in a bathroom or kitchen. I've also used it to treat edges on solid wood worktops for years and it reduces the tendency for cracks to form between the staves at Belfast sink cut-outs

And what brand lacquer would you suggest?

What would you be happy with? I'm a great fan of Sadolin products - not cheap but highly durable

By the way I may have got it wrong in regards to what type of timber it is and after looking at pictures on internet I think it may be birch and not beech. Although not sure if birch can grow to that girth size

As you say birch is generally fairly small diameter logs. Most probably beech.

[mahoak]

J&K thank you for the sound advice, as always. I'm getting the ABEK1 P3 press to check filters for the mask and the gloves (already got the eye protection). Also getting a decent woodworm treatment (which I will apply in the outhouse), the Bonda Voss hardener and the Sandolin lacquer and some cheap brushes. And will get straight to work

[Job and Knock]

You may have noticed that I can't spell permethrin, either. Sorry about that.

To quote from another source (Wikipedia, although I've gone off and read-up some COSHH data on the permethrin products we used on our own house):

"Permethrin has little systemic absorption and is considered safe for topical use in adults and children over the age of 2 months. The FDA has assigned it as pregnancy category B. Animal studies have shown no effects on fertility or teratogenicity, but studies in humans have not been performed."

and

"According to the Connecticut Department of Public Health, permethrin 'has low mammalian toxicity, is poorly absorbed through the skin, and is rapidly inactivated by the body. Skin reactions have been uncommon.'"

which leads me to conclude that any risk to humans would come from ingestion or inhalation (or possibly through absorption through the eyes). However

"Excessive exposure to permethrin can cause nausea, headache, muscle weakness, excessive salivation, shortness of breath, and seizures. Worker exposure to the chemical can be monitored by measurement of the urinary metabolites, while severe overdose may be confirmed by measurement of permethrin in serum or blood plasma."

But how much is excessive? I think there is a major difference between someone using it on a daily basis in a timber treatment firm and a very occasional user. The same is true with a lot of other chemicals, e.g. solvent paints, petroleum spirits, CCA wood treatments, etc. While

"Permethrin does not present any notable genotoxicity or immunotoxicity in humans and farm animals, it is classified by the USA EPA as a likely human carcinogen, based on reproducible studies in which mice fed permethrin developed liver and lung tumors. It is known to be highly toxic to fish and aquatic species."

As it happens sugar is also classed as a likely human carcinogen, as are sulphites used in the preservation of meats like bacon. I believe it is the latter fact above (toxicity to aquatic life) which has brought about controls on the product in the UK where the water companies in particular are concerned about the effects of permethrin entering rivers in large quantities upstream of (commercial) fisheries

[mahoak]

No worries

It looks like whilst the internet is useful for some things it can also be misleading (if topic not researched properly). With all the protection I am using and considering it is being done in the outhouse and a one off project, I think it is quite safe.

[mahoak]

One very last question if I may J&K. What surface would 500ml of Bonda Voss cover? The wood surface is solid and good quality. The whole surface of the wood is 2 sq m. Would 500ml be sufficient for 2 generous coats?

PS: In regards to varnish I'm going for Sadolin Yacht Varnish.

[OchAye]

Can anyone recommend any woodworm treatment that is non toxic and doesnt contain Permethrin or Cypermethrin (or any kind of dangerous chemical like that) please?

I recently used this https://www.everbuild.co.uk/product/tri ... treatment/ and checking the spec sheet it does contain permethrin and reading about permethrin it does not seem as the worse chemical you can come in contact with, in fact according to wikipedia it is classed as an essential medicine.

Just in case you decide to use it, Toolstation had it (although I got it elsewhere), only comes in 5lt tins, and the instructions were more or less to soak the wood. Otherwise, it is very interesting to read what J&K says about it.

[Grendel]

When I first started work treatment was commonplace ,liquids both spirit and water based and mayonnaise paste were used. By twenty years ago it had largely begun to fall out of fashion probably because people had one eye on future lawsuits if someone were to be harmed by such products. When I worked at the Bodlien library in oxford there was no chemical treatments used at all . Instead to combat woodworm spiders were introduced into the roof spaces to prey upon the beetles before they could breed and lay their eggs. There is also the train of thought that if timber is kept dry and stable such as it using in a centrally heated building then insect infestation is much less likely. That one I always took with a pinch of salt , there is some truth in it with regards to some species of woodworm but I don't feel it holds true for all.
Going slightly off topic has anyone here ever heard the knocking of death watch ? I've read about it at college and then one day at lunchtime on a job near Shrewsbury sitting quietly heard this knocking noise. It was really quite loud and we followed the noise to find a beetle rapidly banging its head on the window board. Remarkably loud for such a small creature.