Re: [ARSCLIST] shellac and acidity

[Samuel Brylawski <sbry@xxxxxxx>]

Graham's #2 example doesn't address Kurt's question related to 78s, is
there real evidence of acidic sleeves affecting *shellac*. I'd still be
interested in hearing of examples.

Sam


On Fri, 23 May 2003, Graham Newton wrote:

-SNIP-

> Kurt also said...
> > > What I have not seen (as far as I know) is any record obviously affected
> > > by an acid-laden sleeve. Has anyone else?
>
> Yes, and see item 2 below for an example of this problem.
>
> 2.  A series of 78 rpm lacquers of Brazilian pianist Guiomar Novaes were
>     stored in a conventional multi-page album set over many years under moist
>     warm climate conditions.  Upon looking at these discs, some were noted to
>     be exhibiting an almost "black rash" blistering of the lacquer surface.
>
>     This was puzzling since dubs from these very discs had been made by
>     others with some success a number of years earlier, and the "black rash"
>     did not exist at that time.  Upon examining the album pages, some
>     discoloration and marks conforming to the location of the "black rash" on
>     the discs were noted.  It appears that the album set was made of high
>     acid content paper, and that the moist warmth of the storage conditions
>     had released enough of the acid which contributed to the damage of the
>     lacquer coating of the discs.
>
>     Not all the discs in the set were damaged, and the ones that exhibited
>     the problem did not show a uniform coverage of the "black rash". Some
>     showed a splotchy occurrence, and the worst covered almost half of the
>     surface on the affected disc side.  The worst cases were still playable
>     but the damage produced a very high noise level and made listenable
>     recovery of the material impossible.
>
> The above is probably the most compelling reason to remove any valuable
> artifacts from old sleeves and store them in recently made sleeves that are
> known to be made of low or non-acidic paper.  Once the artifact is damaged,
> it is less likely to be recoverable, as in the case of the lacquers
> described here.