1991 German wooden desk phone

[countryman]

I did not mention caustic soda (sodium hydroxide) because it is unsafe to use. It gives great results in removing old oil paint and old style varnish from wooden items though, better than paint stripper. Use proper protection!
Our professor in the chemistry practical was quite relaxed when someone spilled acids, but was serious about caustic soda.
Sodium carbonate is mild in comparison, but still alkaline enough to remove fat-like materials by saponification. It can also be used on painted objects to degrease them for repainting.
Sodium bicarbonate won't do much for cleaning.

[FABphones]

Great thread. Great find.
Thank you countryman.

[david@london]

Countryman,

your wooden fernsprecher is a really nice design... is it in fact made of oak?
Quite similar to the Swiss Gfeller Trub from the 1970s, which I think were originally made from Rosewood (possibly Acacia).
Have had a hankering for one of those for quite a while.

http://maas-interface-exhibition.s3-website-ap-southeast-2.amazonaws.com/object/trub-telephone/index.html

[countryman]

Nice :-)
Going after the color and grain of the wood I'd say my phone is oak, as labelled.