From: Patent Tactics, George Brock-Nannestad


it was, at least in Europe, and frequently the result is horrible today: the 
oxidation of zinc under a lacquer layer might appear worse than that of iron, 
because it was more even, and adhesion might be so lacking that the lacquer 
curled up in little scrolls  inch by 1/16 inch in diameter. Zinc feels 
heavier and more limp than aluminum, at least to me.

Best wishes,



> From: John Dawson <[log in to unmask]>
> > So while we are on the topic, how about Zinc discs?
> Good question.  I am not sure if it was every used as a substrate in the
> lacquer era. It might not have had good adhesion and was very heavy. 
> But a non-magnetic heavy disc might turn out to be zinc. 
> Zinc had two places in phonographic history.  Berliner used it in the
> 1890s as material that was acid-etched after a groove in a wax coating
> was cut to reveal the zinc that a bath in acid would create the groove. 
> This was necessary to avoid the patents that controlled cutting a
> groove.  The acid created the groove that was actually used for
> mastering or playback.  In the 1920s there was a pre-grooved zinc disc
> that you could put on your acoustical phonograph and when you shouted in
> the horn it would create dimples in the pre-groove which could faintly
> produce sound when played back.  One of these discs had the apt name of
> Echo.
> Mike Biel  [log in to unmask]