At 10:47 AM 9/15/2005, Bev Lambert wrote:
>I might be a bit late in commenting but:  vinegar syndrome is to be 
>predicted on any acetate based film -whether it be audio, moving 
>picture, microfilm or still negative material.  It has a predictable 
>life span -of about 40 years, if kept in reasonable good stable 
>conditions, after which it will start to deteriorate exponentially. 
>Cold storage slows down the process.
>     Several years ago a detection system was developed by IPI 
> (Image permanence Institute), I think in collaboration with a 
> Canadian group.  These are commonly know as AD strips. Blue strips 
> are put into the container with each tape at room temperature, 
> overnight, and examined next day by comparing to colour strips on a 
> pencil. The colour will give you an indication of what stage of 
> deterioration (VS) the tape is at and the guide will tell you how 
> much time in years you have before you can forget about even 
> reformatting the stuff.  The detection kit is available from IPI in 
> Rochester.  Check out
>    Excuse me if this is something you are already aware of.
>Bev Lambert
>Conservator for the Provincial Archives
>The Rooms
>St.John's, Newfoundland, Canada

Hi, Bev,

It's always good to remind people about the IPI strips.

Your matter of fact comment: "It has a predictable life span -of 
about 40 years." should be carefully considered by any archives 
holding acetate tapes.

The fact that I was able to play 55-year-old acetate tapes and I have 
some 40+ year acetate tapes in my collection that are doing fine and 
I see 40+ year old acetate tapes that are fine, doesn't mean that the 
guidelines for preserving sounds shouldn't be to transfer the tapes at age 40.

We all play a form of Russian Roulette when we don't transfer aging 
acetate tapes. The question is: how many chambers, how many bullets?

My two recent posts on the subject is to alert people that there are 
potential accelerating factors that need to be considered in addition 
to the widely known ones:
   (1) Kodak brand acetate tapes
   (2) The 3M auto-threading reel



Richard L. Hess                           email: [log in to unmask]
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