Re: [ARSCLIST] shellac and acidity

[Steven Smolian <smolians@xxxxxxxxx>]

It stands to reason that there would be chemical changes to recording media
based on their ageing and that of their storage holders.

I've noticed a thin film on Victor later acoustics in otherwise superb
condition and have long wondered if this was leaching of some material used
in the original shellac mix.  It might be worth someone's time to analyze
this film.

It would be helpful to know exactly which discs are in question.  If they
are Pathe and associated disc companies, their thick sleeves turn more brown
than those for most other makes, and may be causing a problem.

Do records appear different than those in similar condition and of the same
make and time of manufacture when stored in different kinds of sleeves?

I have just had another instance of wetting the playing surface of an
embossed recording medium with a chemical solution, in this case a dictation
belt, which caused the signal to loose most of the crackling commonly
attributed to dirt and wear.  I now believe, more firmy than ever, that this
temporarily reverses the ageing process for a brief period.  This works as
well, with different chemicals, on  some brands of lacquer discs as I
demonstrated at a UNESCO meeting some 13 years ago.

In all successful cases I know of so far, the surface was a variation of
cellulose acetate.  Yet I've tried my whole chemical arsenal on cellulose
acetate based Blue Amberol cylinders with no effect.

I firmy believe that a study of the chemistry of old recording media will
show ageing patterns and appopriate solutions (pun intended) can be
developed to restore the playing surfaces to a much lower level of
background noise.

I've had some moderate success using experimental mixes on some 78s of the
1920s.

This is independent of wear and abuse damage, of course.

One consequence is that the excess liquid goes into the innards of the
players. As a result, my repairman, Mr. Fix-it, calls me Mr. Break-it.

Steve Smolian

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Steven Smolian    301-694-5134
Smolian Sound Studios
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Five or one or lifetime hoardings,
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----- Original Message -----
From: <alain.carou@xxxxxx>
To: <ARSCLIST@xxxxxxxxxxxx>
Sent: Friday, May 23, 2003 9:19 AM
Subject: [ARSCLIST] shellac and acidity


Dear ARSC Folks,

I have recently inspected several shellac discs albums and observed that in
some
cases, the discs seem to have absorbed the acidity of sleeves. In the
corners of
the sleeves, colors have fainted, which is generally considered as a sign of
acidification, whereas the part of the sleeves which is directly in contact
with
the disc keeps its original color. Does anyone know why, because I wonder if
this could be a sign of chemical interaction between discs and acid paper ?

Thank you.

Alain Carou
Bibliothèque nationale de France
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