[78-L] Graphite?

[Don Cox]

On 26/01/2013, Rodger Holtin wrote:

> This is a new one on me, too, but I've led a sheltered life.
> 
> When might this magic dust have been marketed? Teens? Twenties?
> Thirties? Surely not after semi-permanent needles, or was it?
> 
> This is a UK seller, so I ask: was this stuff used/marketed in the
> USA, too? I have cleaned a few records that seemed to have some awful
> black stuff on them, but always attributed it to smoke or soot.
> 
The black pigment in the records is basically soot, known industrially
as Carbon Black. Almost anything black that you buy has this in it.
Making it is a profitable business.

Graphite is chemically the same but in a more flaky form, as used in
pencils. Graphene is graphite in particularly large flakes, or sheets of
atoms.

I guess if the shellac was not fully mixed with the carbon black, or if
the shellac degenerated, some of the black would rub off.

But black stuff on the surface could well be soot from coal fires. It
would come in through windows.

Regards
-- 
Don Cox
doncox at enterprise.net