Re: arsclist creating sticky shed deterioration

[Parker Dinkins <parker@xxxxxxxxxxxxxxxxx>]

on 5/14/01 3:44 PM, Sarah Stauderman wrote:

We had extensive conversations with Delos Eilers and Bill Lund at 3M's Audio
Video Technology Lab several years ago on this issue.

It was their feeling at the time that the mere presence of moisture did
nothing to hasten the onset of the sticky shed syndrome, but instead it was
caused by the breakdown over time of long chain polymers/molecules which
invited water/moisture to occupy spaces otherwise not available.

Mr. Eilers was kind enough to give me a copy of the notes of the speech he
gave on this topic at an AES meeting. These notes documented his recommended
times and temperatures for re-curing the binder compound by baking.

It's important to keep remember that tapes can have many different problems.
In discussing sticky shed syndrome, you're talking about a specific problem
with open reel analog audio tapes manufactured largely in the US between
1975 and 1985. 

Later. 

Parker

Also: http://www.masterdigital.com/24bit/analogtape.html#anchor1163399

>> Do you think if I leave a reel of 1981
>> vintage 456 in my bathroom for a month of showers it will be hydrolized
>> enough?
> 
> This has been part of the problem for studying tape deterioration:  as far as
> I know, no one has been able to create "sticky shed" in the lab.  It makes it
> really tough to determine what physical mechanism causes deterioration.
> 
> As far as the weight and thickness of Pellon (other brand names are Hollytex
> and Reemay), I believe that the one used for our experiment was 4 mil (thin).
> 
> Sarah Stauderman
 

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Parker Dinkins                      CD Mastering + Audio Restoration
MasterDigital Corporation               http://www.masterdigital.com