Silky Oak Timber - White powder in pores

[Karen]

373714Hi

Restoring a silky oak dresser. After removing old finish, a white substance became visible in the pores of the timber. Sanding did not remove it. It appears to be through the entire thickness of the timber. I am sure it is not paint as it is on the underside of the boards.

At first I thought it was grain filler.

After sanding I gave the timber a light coat of boiled linseed oil and gum turpentine, the white seem to disappear, and left it for a week.

Then I coated the dresser with Feast & Watson Scandinavian oil. All looked good and no white, so I added a second coat.

After 24hr the white became visible on just two of the boards. It is a white powdery substance and can be loosened out with a fine scalpel but not removed completely.

Does anyone have an idea of what it is and how it can be dealt with.

Cheers
Karen

[Lyle]

Talcum powder used in old furniture? As filler. But I would have thought that it would have been absorbed and coloured by the shellac etc. But if it is not a filler and is through the full thickness of the board, then it must be dried sap perhaps.
Sorry best I can come up with.

[Karen]

Hi Lyle
Didn't know they used to use talcum powder. Do you think it could be fungus. There are dados where a shelf is fitted - just raw wool, no old glue or finish?

Thank you for your help

Cheers Karen

[Lyle]

On a clean untreated area, eg underneath. Try some sanding sealer, sand, then some shellac, sand then your finish.
The shellac might disguise the white by absorbing some of its colour.

[Xanthorrhoeas]

I have found a similar phenomenon in some, but not all, old, never used, boards of Northern Silky Oak that I purchased on this forum. At first I was concerned that this would ruin my workpiece, however, when I finished the final product with my usual brown button shellac the white specks disappeared. So, from my experience, it would seem that Lyle's solution will work (and the exact type of shellac is unlikely to matter).

[Mobyturns]

Northern Silky Oak (Cardwellia sublimis) can get the small white deposits within the grain. It is a naturally occurring inorganic deposit (Aluminium Succinate) which has been reported and researched. There have been reports of large volumes in voids of some trees one reputedly up to 25 feet long. Refer to a CSIRO publication "An Occurrence of Aluminium Succinate in Cardwellia sublimis"

My Dad worked a lot with Silky Oak in the 1960's through to late 1980's and we would often come across boards which exhibited the white flecking. i have some reclaimed timber here which has veins of the Aluminium Succinate through it as well as the flecking. The image you attached is typical of the inorganic deposits.

JohnG could confirm this as well as he mills a fair bit of silky.

[Karen]

Thank you Lyle, gave it a try and it seemed to work

Cheers
Karen

[Karen]

Thank you Xanthorrhoeas

I have never used shellac before and do not feel confident. Have you tried hard shellac and is it easy to use?

Cheers
Karen

[Karen]

Thank you Mobyturns
The article was interesting. Very happy to know it isn't fungus.

Cheers
Karen

[Xanthorrhoeas]

Thank you Xanthorrhoeas

I have never used shellac before and do not feel confident. Have you tried hard shellac and is it easy to use?

Cheers
Karen

Hi Karen,

Do not be afraid of shellac - it is one of the easiest finishes to use, and apart from Hard Shellac, is easy to correct mistakes as you just use metho to remove it. Hard Shellac is also easy to use but not so easy to remove once it has cross-linked.

I often use UBeaut's Hard Shellac to seal carved platters and also for wooden coasters. The concentrate can be diluted with as much metho as the solution that you are making up (1:1) and, as long as you keep it in a sealed container, I have not found the unused portion to go off. I apply it with a "rubber" a ball of cotton wool wrapped and tied or sewn in lint-free cloth cover (a piece of an old cotton sheet works well). Use powder-free gloves so it doesn't get on your hands (and no powder on your workpiece). After use I leave the rubber in a sealed plastic container with some clean metho (in between projects) my current one is a reused yoghurt container but I have used better quality containers in the past. The only hitch with the technique is to make sure that the rubber is only moist, not sopping with the shellac, as that creates runs.

There are other suppliers of Hard Shellac (e.g. Shines Shellac) but I haven't used them. UBeaut also sells other shellac in ready-made solutions including White Shellac if you do not want to impart any colour.

I hope this helps.

David