Ebonite

I am currently working on an electrical induction coil in a
collection of historic scientific instruments and I am looking to
identify the material of the insulation on the outside of the coil.
I have read that this material could be Ebonite/Vulcanite but most
references say that this is a stable material resistant to humidity,
acids, solvents, oxidation etc. which does not seem to have been the
case here. On surfaces that have not been directly exposed to the
environment the material is black and smooth but the outside of the
object is covered with white crystals and the material itself has
turned light brown with pale spots. It has been poorly stored with
periods of extreme humidity caused by a leaking roof.

Is there anyone who has experience in the conservation of this type
of material and have encountered degradation of this kind and would
know how to treat the surface? What does the white crystals consist
of? Perhaps someone can give advice on how to clean it and remove
the crystals formed on the surface without causing more damage to
the material?

Christina Hallden
Konservator/Conservator
Centrum fur vetenskapshistoria
Center for History of Science Kungl. Vetenskapsakademien
The Royal Swedish Academy of Sciences
Fax: +46 8-673 95 98


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                  Conservation DistList Instance 14:48
                 Distributed: Thursday, March 22, 2001
                       Message Id: cdl-14-48-012
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