Re: [ARSCLIST] Recording Disc Preservation/Off-gassing?

[Robert Hodge <rjhodge@xxxxxxx>]

Hello Steve ,

I want to be able to give you a proper solution , I wouldn't use
alcohol on a lacquer disc as it will mottle the surface, drying it out,
and make the disc even more noisy than it already is and possibly
stripping the lacquer from the surface if there are any minute cracks in
the surface.

  I'd try an oil based cleaner or maybe vaseline in an unrecorded
portion of the disc, and see how that turns out. Turpentine is also
something that might work as it will not dry out the surface such as
alcohol, benzine , or other highly volatile petroleum distallates will
do . A Q tip sized test should prove how well it works.

Has anyone ever tried these ? I'm not a chemist, but I  have experience
in these areas learned in the school of hard knocks over many years- and
yet to graduate....( has anyone ever graduated ? )

Bob Hodge
Belfer Audio Archive
Syracuse University


>>> stevena@xxxxxxxxxxxxxxx 1/4/2005 2:17:14 AM >>>
Isopropyl alcohol? Hmmm. I'll test that. "A friendly university
chemist"
is also a good idea. I saved only one of the delinquent sleeves, but
it
should offer clues enough for a chemist.

I regret the marking of the surface.

The lesson of hindsight: when you wonder if the match of materials is
"OK," it's best to pretend it's not, and you'll live happily ever
after.
Proceed to guess at your own risk.

Steven Austin

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of James Lindner
Sent: Monday, January 03, 2005 8:26 PM
To: ARSCLIST@xxxxxxxxxxxx
Subject: Re: [ARSCLIST] Recording Disc Preservation/Off-gassing?

I suspect the sleeves are the bad actor, and I doubt that it is
off-gassing
but rather the plasticizer in the sleeves themselves. I have seen
similar
sleeves used to store 35mm slides that were supposed to be "archival"
cause
similar goo and patterning where they came into contact with the film
(unfortunately).

I would suggest that you try a different solvent that might provide
better
results then water. You might try some surfactants although I doubt
that
the
results will be very good. The tackiness will probably still remain
but
I
would then move on to slightly more aggressive solvents. You might
find
that
ISO would do the job. I do not claim to know anything about the
sensitivities of the disks you have - so that is of course the first
priority - but with other media I have sometimes had some success with
common ISO - lab grade with a lower percentage of water and Texwipes.
I
have
used ISO Swabs sold in the local pharmacy on occasion - they work well
but
may lint in your application. If that did not work - I might take a
sample
of the sleeve and the gook to a friendly university chemist to figure
out
precisely what you have - and then find a solvent that is unfriendly
to
the
gook but friendly to the disk chemistry. If the gentle solvents don't
work -
there is no shortage of very aggressive solvents that will certainly
remove
the goo - lighter fluid for example works on many different
plasticizers
and
there are commercial products like "goop off" but they may also
destroy
the
recordings - so be very careful. Parenthetically - I have seen
markings
like
the ones you mention that while visible do not interfere with the
playback
since the contamination only occurred on the top surface of the
recording
and not inside the groove.

jim
*
        Jim Lindner
*
        Media Matters, LLC
*
        Email: jim@xxxxxxxxxxxxxxxxx
*
        Address: 500 West 37th Street, 1st FL
        New York, N.Y. 10018
*
        eFax (646) 349-4475
*
        Mobile: (917) 945-2662
*
        www.media-matters.net