Thread: Identity of wood that smells like tar

Could it be creosote that was applied to the timber to preserve it perhaps?

Originally Posted by cava

Could it be creosote that was applied to the timber to preserve it perhaps?

A very perceptive answer

I don't know about that form of treatment. There were also red cedar and red gum timbers in the building and they don't smell like this stuff. I think that if they'd treat one timber with something they'd do all of them. But, I wasn't around in the 1800's so have no idea what was done back then.

Could be Turpentine.

Yes that had crossed my mind.

Turpentine may well be it. I just found some info that included the following sentence:

The extractives produce dark brown stains on alkaline surfaces, such as concrete and fibre cement.

This has happened to my concrete floor where the timber was standing when the floor became wet during the recent storms. I haven't yet found any reference to the smell of the timber.

Originally Posted by cava

Could it be creosote that was applied to the timber to preserve it perhaps?

Hard to tell from the pics, but it doesn't look like Turpentine - maybe more like Tallow Wood. Last year I machined a great many joists that were creosote coated and once the top 1½-2mm layer had gone I don't recall still smelling the creosote. Then again there are those black parts on the turning. Do those parts have a stronger smell?

That said, creosote smells just like tar (I've just applied some last week).

Another clue may be the silica content - Turpentine is loaded with it and will blunt tools very quickly indeed. More than the usual sharpening during the turning?

EDIT: As far as I know, creosote wasn't generally used on timbers above the floor, but of course different operators will use it in different ways.

Originally Posted by Jonnydubbs

The extractives produce dark brown stains on alkaline surfaces, such as concrete and fibre cement.

This has happened to my concrete floor where the timber was standing when the floor became wet during the recent storms. I haven't yet found any reference to the smell of the timber.

Tallow wood is a classic for this leaching of tannins. I was told this by the paint people in the hardware, and had also observed it myself, and they advised to use two coats of primer for the TW windows that I made. Even then and after three top coats, the tannins have still come out in places. TW also fits the bill of "very hard and very heavy".

It might be worthwhile determining the specific gravity of the timber (volume/weight) as that will give a better clue.

Without having spent a lot of time on the research, Turpentine seems to have a SG of about 0.945 and Tallow wood about 0.99 to 1.09, (both at 12% moisture), so TW seems to be a little heavier than Turpentine.

Thanks for the input. Regarding the silica content and blunting of tools, this turning was pretty hard on the tools, and my saws work fairly hard ripping and cross-cutting it. Looking at the row of nail holes in the pictured piece of this wood, that I've run through the thicknesser, I'm assuming it was below floor; probably floor joists. The last photo is of a piece of what I know to be Tallowwood that I cut from Martinsville NSW. Possibly they are the same timber. The dressed piece has lost the strong smell as has been suggested once you get 1.5-2mm in from the surface so it seems the evidence is strengthening toward a Tallowwood ID.

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I don't know if TW retains its greasy feel 130 years later, but it probably does internally. That would be another indicator for TW + creosote (smell).

Looks a lot like the timber I 'borrowed' from the neighbours house when demolished - floor joists
at the time I though maybe spotted gum
It's as had as and is also a bit over 100yo
thing is could be anything as the builder would have asked for 'hardwood' and would have got whatever was local to the sawmill