[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: odors coming from Audio and video collections



Jim Lindner wrote:test
>
> I thought it may be helpful to comment on some of the comments.........
>
> First of all, "vinegar syndrome" specifically relates to the break down of
> acetate based materials. Acetate has been and is used as a support on many
> different types of products, but motion picture roll film and other types of
> roll films are  usually the culprit in these situations because there is a
> high density of the material usually stored in a sealed or semi-sealed
> container.  Once the concentration of acetic acid reaches a certain level,
> the reaction becomes auto catalytic - which means that the film literally
> eats itself - i.e. the acetic acid present causes more film to break down
> into more acetic acid and so forth. Depending on the severity of the problem
> there are a number of remedies - but ultimately the solution is to recopy
> the film and make a new copy. This is NOT done by Kodak, but IS done by
> professional motion picture film laboratories who specialize in this type of
> work (VidiPax is NOT one of them).
>
> Videotape has NEVER repeat NEVER been manufactured on acetate based stock -
> it has been made on a variety of PET type materials - to most of us that
> means polyester. Polyester does NOT get vinegar syndrome since there is no
> acetate at all. Videotape does have other major problems which cause
> degeneration  but vinegar syndrome is not one of them.
>
> Audio tape HAS been manufactured on acetate, but it was not very popular and
> while it does exist and therefore it could develop vinegar syndrome, the
> reality is that it rarely happens. There are many theories why it is not a
> major problem, but it probably gets back to the density issue. At vidipax we
> have restored thousands of audio tapes and while they too have major
> problems, vinegar syndrome is extremely rare, and I have never seen an audio
> reel to reel acetate based tape degenerate at anywhere near the level of
> motion picture film.
>
> There are magnetic films that are acetate based, and if Van Bogart referred
> to magnetic FILM, then this is what he is referring to NOT MAGNETIC TAPE.
> Magnetic Film is VERY different material then regular audio or videotape -
> it is magnetically coated acetate film that is used in motion picture
> productions. It basically looks like film except it is usually either brown
> or gray which is the magnetic coating. It has sprocket holes and can be
> either 16mm or 35mm. Unfortunately there have been major problems with these
> types of films getting vinegar syndrome as well as other problems. In some
> respects this media type has the worst of all worlds from a preservation
> point of view - it has the problems of both magnetic binders and acetate
> base films.
>
> The best way to slow down the process is to keep the materials cool and dry.
> There are products like molecular sieves which will slow down the process
> somewhat but ultimately you really have to recopy the film and the longer
> you wait the worse it will be - so the remedies suggested in some of the
> postings may slow down the degeneration but WILL NOT reverse or halt it.
> With film the materials can be frozen in the CORRECT ENVIRONMENT i.e. low
> humidity. Magnetic tape (audio or video tape) should also be kept cool and
> dry but NOT frozen. There is a great deal of documentation on this
> ubject  - for further information one might consult the SMPTE (Society of
> Motion Picture and Television Engineers) and ANSI for standards and
> recommended practices for the long term storage of motion picture,
> photographic, and audio and video materials.
>
> I hope this helps untangle things a bit.  (ha ha)
> jim
>
> Jim Lindner - President
> VidiPax - The Magnetic Media and Information Migration Full Services Company
> Telephone 212-563-1999
> www.vidipax.com
> Moderator of A/V Media Matters@topica.com
>
> > -----Original Message-----
> > From: Archives & Archivists [mailto:ARCHIVES@LISTSERV.MUOHIO.EDU]On
> > Behalf Of Jones, Virginia
> > Sent: Thursday, May 11, 2000 2:54 PM
> > To: ARCHIVES@LISTSERV.MUOHIO.EDU
> > Subject: Re: odors coming from Audio and video collections
> >
> >
> > Rob:
> > Vinegar syndrome can occur in any "acetate" base material.  Dr. John Van
> > Bogart of the National Media Lab defines vinegar syndrome as
> > "characteristic
> > of the decomposition of acetate based magnetic tape where acetic acid is a
> > substantial by-product that gives the tape a vinegar-like odor.  After the
> > onset of the vinegar syndrome, acetate tape backings degrade at an
> > accelerated rate - the hydrolysis of the acetate is catalyzed
> > further by the
> > presence of acetic acid by-product."  ("Magnetic Tape Storage and
> > Handling,
> > A Guide for Libraries and Archives", Dr. John W. C. Van Bogart,
> > published by
> > The Commission on Preservation and Access, June 1995)  Both your
> > audio tapes
> > and your video tapes are a form of magnetic tape.  Microfilm and
> > photographic negatives manufactured with an acetate base material are also
> > susceptible to vinegar syndrome.  High humidity accelerates the onset of
> > vinegar syndrome as well as some other mag tape binder problems so you may
> > want to investigate how much the proximity to the pool area is affecting
> > your storage environment.
> >
> > Ginny Jones
> > (Virginia A. Jones, CRM, MIT, LIT)
> > Newport News Waterworks
> > Newport News, VA
> > vjones@ci.newport-news.va.us
> >
> > > -----Original Message-----
> > > From: Rob Dishon [mailto:rdishon@LAGCC.CUNY.EDU]
> > > Sent: Thursday, May 11, 2000 1:47 PM
> > > To: ARCHIVES@LISTSERV.MUOHIO.EDU
> > > Subject: Re: odors coming from Audio and video collections
> > >
> > >
> > > But doesnt vinegar syndrome only effect negatives...  I wasnt
> > > aware the modern day audio and video tape had the same
> > > properties as negatives.   My photo and negative collections
> > > are in another storage area.
> > >
> > > A posting from the Archives & Archivists LISTSERV List!
> > >
> > > To subscribe or unsubscribe, send e-mail to
> > > listserv@listserv.muohio.edu
> > >       In body of message:  SUB ARCHIVES firstname lastname
> > >                     *or*:  UNSUB ARCHIVES
> > > To post a message, send e-mail to archives@listserv.muohio.edu
> > >
> > > Or to do *anything* (and enjoy doing it!), use the web interface at
> > >      http://listserv.muohio.edu/archives/archives.html
> > >
> > > Problems?  Send e-mail to Robert F Schmidt <rschmidt@lib.muohio.edu>
> > >
> >
> > A posting from the Archives & Archivists LISTSERV List!
> >
> > To subscribe or unsubscribe, send e-mail to listserv@listserv.muohio.edu
> >       In body of message:  SUB ARCHIVES firstname lastname
> >                     *or*:  UNSUB ARCHIVES
> > To post a message, send e-mail to archives@listserv.muohio.edu
> >
> > Or to do *anything* (and enjoy doing it!), use the web interface at
> >      http://listserv.muohio.edu/archives/archives.html
> >
> > Problems?  Send e-mail to Robert F Schmidt <rschmidt@lib.muohio.edu>
> >
>
> A posting from the Archives & Archivists LISTSERV List!
>
> To subscribe or unsubscribe, send e-mail to listserv@listserv.muohio.edu
>       In body of message:  SUB ARCHIVES firstname lastname
>                     *or*:  UNSUB ARCHIVES
> To post a message, send e-mail to archives@listserv.muohio.edu
>
> Or to do *anything* (and enjoy doing it!), use the web interface at
>      http://listserv.muohio.edu/archives/archives.html
>
> Problems?  Send e-mail to Robert F Schmidt <rschmidt@lib.muohio.edu>

A posting from the Archives & Archivists LISTSERV List!

To subscribe or unsubscribe, send e-mail to listserv@listserv.muohio.edu
      In body of message:  SUB ARCHIVES firstname lastname
                    *or*:  UNSUB ARCHIVES
To post a message, send e-mail to archives@listserv.muohio.edu

Or to do *anything* (and enjoy doing it!), use the web interface at
     http://listserv.muohio.edu/archives/archives.html

Problems?  Send e-mail to Robert F Schmidt <rschmidt@lib.muohio.edu>