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Lisa Lobdell wrote:

> Hi, I'm brand new to this list and was completely ignorant of the 
> existence of glass albums until last week when I accepted an internship 
> to inventory the collection of a small foundation.  Along with the 
> written documents and LP's in this collection are approximately 6cft of 
> glass albums.  I have no idea yet what the quality of these albums is, 
> but I would appreciate it if someone could give me a quick rundown of 
> what defects to look for and how to preserve them.  I've read some of 
> the threads, but I'm brand new to archiving audio materials so I'm a bit 

Hello Lisa...

Please don't use the word "albums"... an album is a multi pocket jacket usually 
holding a number of related shellac records and usually of one artist.  The 
word carried over to any multiple tune collection on LP record or even extended 
to CD.  These album housings were treacherous for records because most people 
have a tendency to unknowingly flip the "pages" when looking through one, 
catching the inner edge of the disc at the binding and cracking a 1/2 moon 
piece out of a shellac disc and breaking glass discs!

What you have are called a number of things including "instantaneous discs" or 
  "soft cuts".  They are also incorrectly referred to by some people as 
"acetates" and there is not a spec of acetate in them!  They are actually 
cellulose nitrate lacquer, and so the correct name is "lacquer".  Unlike a 
commercial record made by a pressing process, these lacquers are cut one at a 
time, and usually housed in single sleeves.

In your case, the base material is fragile glass (with a protective fibre 
center plug for the center and drive holes) which was a substitute for the more 
common aluminum during the war years when aluminum was needed for aircraft 
production.  They need to be handled like thin glass... which they are.

If you hold one up to a strong light, you will see light transmitted through 
the lacquer coating, usually as a dark blue or reddish color.  You will easily 
see any cracks in the glass that may be hiding under the lacquer coating.

Other base materials are steel and fibre (like cardboard).




... Graham Newton

-- 
Audio Restoration by Graham Newton, http://www.audio-restoration.com
World class professional services applied to tape or phonograph records for
consumers and re-releases, featuring CEDAR's CAMBRIDGE processes.