Dear all, it's nice to see the MMD widening its horizons now to include
sound recording topics.

Edison discs that have delaminated are almost certainly beyond
redemption.  The discs are made of a form of Bakelite ("condensite")
and this is a thermo-setting plastic, meaning once set, they will not
be softened by heating.  Unlike gramophone discs of, say Columbia or
Victor, they will not respond to hot ovens and weights.

Two points of caution:

One: They will have delaminated due to moisture getting into the edges
of these thick discs, so never get them wet whilst cleaning.  A _damp_
cloth is safe enough, in my experience, but avoid getting the edges wet
at all costs.  Edison's claimed that alcohol should be used to clean
them, but again, _never_ clean gramophone discs with alcohol -- you
will dissolve them!

Two: If you decide to play a disc with delamination damage, and you put
the stylus down on the damaged part by mistake, you stand a good chance
of stylus damage occurring -- either serious, obvious damage, or mild
damage which you do not notice at the time, and so go on using the
reproducer, and damaging all records subsequently played.

Sincerely,

Paul Morris

 [ Normally MMD leaves phonograph discussions to other forums, since
 [ audio machines aren't self-playing mechanical musical instruments,
 [ but delamination can occur with punched cardboard media, too.
 [ -- Robbie