Re: [ARSCLIST] A tape Vinegar Syndrome experience

[Eric Jacobs <ericj@xxxxxxxxxxxxxxxxxxx>]

>From my recent research on nitrocellulose discs ("acetates", a
misnomer) and their deterioration, I suspect that VS and palmitic 
acid (PA) share at least one thing in common - they are both 
autocatalytic reactions (ie. VS and PA deterioration are 
accelerated in the presence of acid, and VS and PA both produce 
acid).

I conjecture that an ideal container for tapes would be an
acid-free cardboard box that is buffered.  As a tape deteriorates
and produces acetic acid, the box absorbs and neutralizes the
acids with its buffer.  This mitigates the autocatalytic nature
of VS.

Lacking a buffer in plastic or metal containers, air circulation 
is important to keep the concentration of acid down.  

Given the prevalence of plastic and other semi-inert containers,
it might make sense to just place a piece of acid-free buffered
cardboard in with your tape, which will provide enough of a
buffer to protect the tape from itself.

Nothing like an extra line of defense.  And its relatively
cheap, too.

Eric Jacobs
The Audio Archive
www.TheAudioArchive.com


---- Original message ----
>Date: Fri, 9 Sep 2005 21:12:52 -0400
>From: "Richard L. Hess" <ArcLists@xxxxxxxxxxxxxxx>  
>Subject: [ARSCLIST] A tape Vinegar Syndrome experience  
>To: ARSCLIST@xxxxxxxxxxxx
>
>An update on Vinegar Syndrome in audio tapes. More anecdotal evidence 
>that helps support the well-known rule of storing film in vented cans.
>
>I received four reels of Kodak sound recording tape that were 
>recorded in 1962 and 1963. All are Triacetate backing. Two are 1.0 
>mil on 5-inch reels and two are 1.5 mil on 7-inch reels.
>
>All of the reels were very loosely wound. The two 7-inch reels were 
>in plastic bags inside their boxes. One of them reeked of vinegar 
>when I opened it and when I rewound it. I had to move away from the 
>prep machine during initial rewind.
>
>It did not seem to suffer from any of the loss-of-lubricant we've 
>started to see in Sony reel-to-reel tapes and 3M dictation cassettes 
>(among others).
>
>The outside of the tape pack could be easily depressed 1/4 to 3/8 of 
>an inch, the pack was so loose. I wonder if that much material was 
>lost? The tape still played fine and appeared dimensionally stable, 
>but this is as far gone as any I have seen judging from the odor.
>
>I have never seen this before with tapes stored in the more usual 
>cardboard boxes without being sealed in a bag. Doug Nishimura of IPI 
>has more examples than I, but I am concerned that we're going to 
>start to see significant degradation of acetate-based tapes. The risk 
>of this tape is growing, IMHO.
>
>I'm glad these are getting transferred. They are interviews with 
>people who were at one of the Shaker communities in the early 1900s.
>
>Apologies for the cross posting. I'm not looking to get into a major 
>discussion about this -- just a heads up for those who are keeping 
>track of at-risk media. Probably if we do discuss it, it should be on 
>AMIA-L as that is where most of the knowledgeable VS people reside 
>(due to the issue surfacing in film archives a bit more than in tape 
>archives). If you are interested in the list go to 
>http://www.amianet.org/amial/amial.html
>
>Regards,
>
>Richard
>
>Richard L. Hess                           email: richard@xxxxxxxxxxxxxxx
>Vignettes 
>Media                           web:   http://www.richardhess.com/tape/
>Aurora, Ontario, Canada             (905) 713 6733     1-877-TAPE-FIX
>Detailed contact information: http://www.richardhess.com/tape/contact.htm