78 rpm records

Elizabeth Dunford <elizabeth.rl.dunford [at] googlemail__com> writes

a>I work at a historic house where there is a small but significant
>collection of 78 records belonging to the original owner of the
>house. They all date from before 1950 and are stored in albums.
>...
>I'm finding it very difficult to find conservation information on
>the care and even the manufacture of these objects and would value
>any help available.

>... What would they be made of? ...

Generally 80% mineral matter and ca. 20% shellac.  Rosin is almost
always present, and sometimes vegetable fibres (remains of
ground-down paper labels when old records were re-used).  Columbia
records from before ca. 1930 (and later in France and Italy for
sister companies) were laminated: a coarse- grained core and a very
fine-structured surface, still based on shellac as the binder. Here
one may see superficial cracks due to humidity.

>... What could be
>causing the bloom? ...

Very frequently it is a fungal attack, and you see the mycelium.

>... What sort of conditions should they ideally be
>stored in? ...

As you would store books. (cf. AIC Caring For Your Treasures:
"Caring for your Books"

<URL:http://www.conservation-us.org/index.cfm?
    fuseaction=Page.viewPage&pageId=626&parentID=497>)

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>.. Would it be detrimental to move them to drier conditions
>too quickly? ...

Generally, no, not more than for paper.

>.. Can they be restored to be played?

Yes, the fungal remains can be removed, but the etched traces they
have left will remain. The humidity combined with a possible
manufacturing date in the 1940s will have caused fibres to swell and
crack the surface--this is not reversible. There will be a noisy
background that shows the tough life of the record. Replay is easier
on a portable gramophone with steel needles, and it would be period
replay, representative of certain social strata.

As to literature, I would recommend a contribution of my own:

  "Gramophones and Records:  The first widespread commercial
   standardisation"
   in "Incredible Industry. Preserving the evidence of
   industrial society", Nordisk Konservatorforbund, Copenhagen
   2009, pp. 119-126. This is available at:
  <URL:http://www.nkf-dk.dk/Bulletin/NKF-Incredible-industry09.pdf>

Despite the problems I have identified in my suggestions, one must
consider gramophone records to be remarkably sturdy.

George Brock-Nannestad


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                  Conservation DistList Instance 24:48
                  Distributed: Tuesday, April 19, 2011
                       Message Id: cdl-24-48-005
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