There might be something to iron/cellulose reaction.
Keep in mind though, vinegar syndrome can start without iron/cellulose
contacting each other (at least in motion picture film). Prime example:
I received on two separate occasions and from two separate individuals
Super 8mm motion picture films from Hawaii. No mag stripe. All short 50'
lengths on plastic reels, shot in the 1970's. This is quite young for
film. Both collections were stored in a basements of a house that were
not air conditioned and pulled out from time to time to run in a
projector. Otherwise the films were all stored in ziplock bags, and then
by one of the owners also in Tupperware totes. The films would be
exposed to the humid air then placed back in airtight containers. They
had some of the worst examples of vinegar syndrome I have ever seen.
Once job I turned down there was no way to rescue the film. The other
took a ton of patience (and vapors so strong it made your heads spin).
So it is not an iron oxide contact with acetate that alone begins VS,
though it may speed up or begin the process earlier. The main reason for
VS is hydrolysis reacting to acetate.
FWIW I just got off the phone with one of my buddies who was a film
emulsion engineer at Kodak. To the best of his recollection he believes
Kodak made their own acetate based audiotape and the main manufacturing
plant was out of Ireland.
On 3/1/2015 6:21 PM, Tom Fine wrote:
> Here's an idea that may need research -- what if what I'm calling
> "drying out" of acetate-backed tape IS vinegar syndrome, just with no
> vinegar smell? What if different iron oxide formulations cause the
> mechanism to happen in different ways to different degrees, but it's
> all related to iron/cellulose reactions?
> -- Tom Fine
> ----- Original Message ----- From: "John Schroth"
> <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Sunday, March 01, 2015 5:55 PM
> Subject: Re: [ARSCLIST] Distressing data point for upcoming ARSC tape
> playback workshop
>> Hello Nigel:
>> Interestingly enough, at an AMIA conference several years prior,
>> there was an outfit - I cannot remember where they were from, who
>> claimed to have a new chemical process that could not only halt
>> vinegar syndrome but could reverse its effects on motion picture
>> film. Everyone seemed very excited about the announcement, but the
>> group would not release any more information. They have been quiet
>> John Schroth
>> On 3/1/2015 5:14 PM, Nigel Champion wrote:
>>> Hi John
>>> Further to your re-plasticisation technique, a German and Austrian
>>> collaboration researched re-plasticisation of acetate tape with the
>>> results presented at ILKAR. These comments subsequently appeared in
>>> the Summer 2011 ARSC Newsletter 126
>>> "Nadja Wallaszkovits (Phonogrammarchiv, Austrian Academy of
>>> Sciences, Vienna) gave a paper that belied its title `Digitisation
>>> of Highly Degraded Acetate Tapes - A Treatment Report ́. Fortunately,
>>> there was nothing about digitisation! The paper gave a detailed
>>> discussion of one extreme example of plasticiser loss in acetate
>>> tapes, described how plasticiser loss and vinegar syndrome were two
>>> independent phenomena, and showed the result of a novel
>>> re-plastification process for all acetate materials that
>>> is being patented. No details were given, but the patent application
>>> will be published soon. Replastification was contemplated also for
>>> old films, but (in my view) probably the thickness will require very
>>> long processing times."
>>> Has anything come of this research?
>>> Best wishes
>>> -----Original Message-----
>>> From: Association for Recorded Sound Discussion List
>>> [mailto:[log in to unmask]] On Behalf Of John Schroth
>>> Sent: Monday, 2 March 2015 10:34 a.m.
>>> To: [log in to unmask]
>>> Subject: Re: [ARSCLIST] Distressing data point for upcoming ARSC
>>> tape playback workshop
>>> Hi Tom:
>>> Kodak has known about VS for many many years. Early tins from the
>>> 1940's and possibly earlier have a small relief in the inside film
>>> lid that is disk shaped. Inside the relief was 3-4" diameter disk of
>>> thin paperboard with a metal mesh grill covering it to hold the
>>> paperboard in place but allow the chemical put on the paperboard to
>>> slowly dissipate into the film can. The chemical was a solution
>>> mostly containing camphor. It is well-documented that camphor helps
>>> to slow the beginnings of VS. I have used camphor to slowly re
>>> plasticize very dry and brittle motion picture acetate base film
>>> that had VS. Quite possibly the same could be done for audiotape in
>>> the same condition? I got this recipe from someone at LOC.
>>> You place a small amount of natural camphor, 2-3 pieces about half
>>> the size of a sugar cube each, in the bottom of a metal film tin.
>>> (camphor and be easily found at Indian grocery stores - they use
>>> camphor for special ceremonies) With some small wood blocks (or
>>> portions of a pencil
>>> - no paint on the pencil and no eraser because the camphor will eat
>>> paint and eraser) you suspend the film on the reel above the camphor.
>>> Close the lid and seal it. The camphor is dissolved into the film.
>>> It takes many many many months (my latest project has been almost two
>>> years) but the film which was once so brittle, it would easily break
>>> when bent, is now more pliable and depending on how much shrinkage
>>> has occurred. Sometimes you can work with the film enough to scan
>>> it. Again it would be interesting to test this with audiotape in the
>>> same condition.
>>> My quick fix recipe for cupped and curling acetate audiotape is to
>>> increase the tension settings on my ATR reel to reel deck and add
>>> several additional guideposts on each side to keep the tape from
>>> curling over itself on it's way to and from the head block. It isn't
>>> pretty but it has worked for the few times I needed to make a
>>> transfer where the tape is curling so much, it would not make it
>>> from the reel to the first tape guide without curling over on itself.
>>> John Schroth
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