[Q] Tanalised wood, hand tools and health

[Fromey]

Everyone's going to eventually get sick and tired of my questions! (hammer) But here's another. (homer)

Whilst researching for a hand saw, I notice a Barcho that was advertised as, "for use with tanalised wood". That got me thinking about what is specific to tanalised wood that would warrant such a stipulation. Does tanalising somehow harden the wood, making it extra wearing to tools, or is it corrosive to the metal? The name, tanalise, suggests tanic acid, but in fact I think the treatment involves arsenic.

Any advice on whether to use hand tools (saws, planes, chisels) on tanalised wood would be appreciated.

Also, should one be especially careful about sawdust and/or shavings?

Thanks as always.

 

[9fingers]

Tanalised wood is usually delivered pretty wet in my experience and can be very stringy to cut, so maybe the saw is particularly sharp to cut rather than snag on those wet fibres.
If often felt splashes of water/treatment fluid hit me in the face when driving in 4" nails (on some of my finer woodwork projects naturally) :lol:

If tanalising were hazardous, nanny state would be covering it in warnings and only allowing competent persons to handle the stuff. Just wait until it features in Part W of the building regulations :lol:

Bob

 

[joiner_sim]

I cannot reply to the tanalised section of your question really as I do not really know.

However, you did ask:

Also, should one be especially careful about sawdust and/or shavings?

You probably already know the risks to health from dust, but if you don't you should be careful of it. In particularily dusty operations masks and extraction should be used.

http://www.hse.gov.uk/coshh/industry/woodworking.htm
http://www.hse.gov.uk/pubns/wis30.pdf

Hope that helps.

 

[shipbadger]

I too have often noticed that even 'dry' tanalised timber often cuts more like wet wood. I often use one of the Chinese tenon saws that Axminster used to sell with the hard teeth to cut it because of this. When I purchased my new workshop one of the reasons for choosing the supplier was because they had their own tanalising tank and all the wood would be treated. No particular health warning came with the buildings and in this day and age one presumes that if there had been a particular hazard the supplier would have had to provide some sort of CoSHH notification.

Tony Comber

 

[OPJ]

I'm not sure what it is but, tanalised timber does seem to have a blunting effect on the edges of your tools and machines. Treated timber is generally "safe" to handle - provided that the wood has been given forty-eight hours to dry after coming out of the tank (legally, I don't think yards are allowed to sell you anything that's still "wet"...).

Arsenic hasn't been used for a few years, after new EU regulations came in (at the same time as when creosote was banned). Instead of CCA (Copper, Chrome and Arsenic) it should either be ACQ or 'Tanalith E', generally speaking.

Whenever you cut or machine in to pressure-treated timber, you'll need to re-seal any cut areas as you are effectively breaking the seal of the chemicals, which only penetrate about 6mm deep all round. 'Ensele' is probably the most commonly used product for this though, at £15 per litre, it's not exactly cheap... Hence, why you should only use it for sealing sawn ends and notches, etc. - not entire lengths of wood! ;-)

By all means; if you're planning to make something from pressure-treated wood then, it would pay to buy ordinary sawn or PAR wood (untreated), do all the work yourself and then to have the yard treat it for you, either before or after assembly, depending on the size or scale of your project. A typical price for this service might be £15/ft³ + VAT, for example.

Or, you could look at using a product from Ronseal or Cuprinol, etc. (I'm sure Mailee does this). You may find it gives a faster turnaround, being able to do it in your own time. Whatever you decide to do though, even treated timber will require regular maintenance, as with all external woodwork.

 

[Ateallthepies]

I did not know that the tanalising went only so deep and the cut ends needed sealing?

Will remember that next time I use the stuff outdoors.

Steve.

 

[Fromey]

Thanks all for the replies, esp. Olly's details. Yes, I suppose it stands to reason that if it was hazardous, it would have a warning on it. I'm also surprised the preservative penetrates only 6 mm or so. I would have though just soaking the wood in a vat would do that. Surely the reason for the pressure treatment is to get effective and efficient penetration.

RE: sawdust in general. Since I have no power tools other than a router and a hand held circular saw (where I do use a mask), I figured the amount of dust produced by planes, hand saws , etc. would be minimal and not warrant a mask. Also, I'm only a weekend worker, so not much exposure. In fact, the dust I'm most anxious about is metal dust when one flattens plane soles, etc. on normal sand paper.