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Re: [ARSCLIST] Cleaning of grooved discs
On Feb 2, 2009, at 9:27 PM, Michael Biel wrote:
The fluid was excellent on 78's, LPs, and stable acetate
transcriptions. It was especially good at removing the vinegar
syndrome dust that is so common with transcriptions.
What in the world are you talking about??? What you are calling
"acetate transcriptions" are NOT ACETATE, they are NITRATE. Vinegar
syndrome is specific to cellulose acetate, which was used in motion
picture film and recording tape. Since these discs are not made of
cellulose acetate, what you are seeing on them has nothing to do
with vinegar syndrome but has everything to do with the leeching of
the plasticizers used to make cellulose nitrate.
It makes no more sense to call it "vinegar syndrome dust" than to
call it "pixie dust." And these discs should not be called
"acetates", if only to keep people from thinking a lacquer disc can
develop vinegar syndrome.
These discs were indeed acetate, perhaps nitrocellulose acetate. I
stand corrected on the "vinegar syndrome" nomenclature, but I stand by
the tergitol solution. It worked very well. The white dust was
removed, and the sound quality was much better. I don't remember
mentioning pixies, though.
Let me expand on what I tried to explain a few days ago. Prior to
the introduction of cellulose nitrate lacquer coated recording discs
in 1934, there were two types of solid (non-laminated) plastic
PRESSINGS made of cellulose acetate. One was the transparent discs
made by Flexo, and around 1933 this material was used by Brunswick
for 16-inch pressings. The other was a flexible opaque disc with a
slightly greasy feel that was used by World Broadcasting System.
These were clay-colored and were supplied by World with a special
filing case that had a spring-loaded pressure plate in order to keep
them flat when stored. Around 1935 World started to offer stations
an option to get the discs on a thicker and stiffer vinyl pressing
that did not need the pressure plate in the file drawers. But
broadcasters had already gotten into the habit of calling any
plastic discs "acetate." I have never smelled any vinegar on the
Flexo or red World discs, but have smelled vinegar on a special
commemorative Western Electric pressing made around 1933 for Arthur
C. Keller of one of his twin-groove Phila Orch stereo masters, and
on a set of 16-inch ETs pressed by World's manufacturer on an opaque
blue material also around 1933. Now these discs ARE acetate, and
can be considered at risk for vinegar syndrome, but are totally
unlike the lacquer coated recording discs you are familiar with.
There was no dust, no deterioration, only the vinegar smell.
Remember, these are pressings, not recording discs.
The discs I dealt with were locally recorded at a radio station
studio, and not pressings. The oldest were from 1938. Most of them
appeared to be of the "Audiodisc" variety, which are, correct me if I
am wrong, some form of acetate. I found these discs in our special
collections by smelling for them. I caught a whiff, I found the discs.
Maybe I was smelling something else?
The transcriptions, of course, need to be handled very delicately
in the cleaning machine, or cleaned by hand.
We did not have any shellac transcriptions in our collection, so I
can't speak to it's efficacy there, but I would test on a blank
side if one is available by hand with a cotton swab to see if it
would remove any of the shellac. I would be wary. Garry Kling
You did say you had 78s there. Weren't these usually shellac? What
wouldn't harm a shellac 78 wouldn't harm a shellac transcription.
16-inch ETs and motion picture soundtrack discs were pressed of
shellac from the 1920s into the mid-30s. And cleaner reaction isn't
like removing any of the shellac like a shellac coating on
furniture, it usually results in the affected material turning white
on contact of the alcohol.
Mike Biel mbiel@xxxxxxxxx
I suggested the testing because I wasn't sure of the effects of
Tergitol on shellac. Not all 78's are made of shellac, particularly
later ones. Different manufacturers used different formulas that may
or may not have included shellac. But I do suspect, as you do, that a
mild surfactant would not harm shellac. I would just err on the side