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Re: [ARSCLIST] Why sticky shed happened



One of the problems with investigating sticky shed is that a number of
people who have tried to induce the reaction for study purposes have had a
very frustrating time coming up with consistent results.

A number of years back, we did some investigation and found that the
presence of metal ions, when tape was exposed to high humidity, GREATLY
catalyzed the binder degradation.  Just thought I'd throw the information
out there in case anyone wanted to do some additional experiments.

Peter Brothers
President
SPECS BROS., LLC
(973)777-5055
www.specsbros.com

Restoration and Disaster Recovery Service Since 1983

> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx]On Behalf Of Richard L. Hess
> Sent: Monday, June 26, 2006 11:16 AM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] Why sticky shed happened
>
>
> Steve,
>
> The "why?" is interesting from the perspective of knowing what
> happened to specify type-specific cures to type-specific problems.
> The "why?" is very uninteresting from a legal perspective. I hope, at
> this point, no one wishes to redress any losses due to tape
> degradation. Any action in that direction will reduce the limited
> exchange of information we have and that would be counterproductive,
> I believe. On the other hand, manufacturers should not even consider
> attempting to quash the information that comes out of ongoing
> research. This is all over and done with and the only concern should
> be preserving the archives.
>
>  From what I see few to none of the manufacturers are totally
> blameless, and many users have stored tapes improperly to very
> poorly. When pushed to answer the question, I believe that Ampex said
> in those days, "if it's important, I'd copy it within 10-15 years."
> While that is probably conservative, no medium is permanent. Even
> paper isn't, but it does the best job (assuming it's acid-free) short
> of stone tablets. (Yes, I know that some stone tablets fail when
> exposed to acid rain...)
>
> My current concerns in no special order are:
>
> (1) Base film degradation for acetate tapes
> (2) The increase some of us are seeing in the required incubation
> times to make SSS tapes playable
> (3) The tapes that show some sort of degradation (what we've been
> calling "Loss of Lubricant" (LoL)) and squeal upon playback and don't
> respond to the normal incubation process.
> (4) Tape layer adhesion, mostly on non-back-coated tapes, where it's
> either full blocking or pinning at a few points of the outer layer's
> oxide to the inner layer's backing.
>
> I think the research into all of these failure modes and ways of
> prolonging the life of the tapes that we wish to keep but can't
> afford to transfer and also ways to optimize playback now should that
> route be chosen are the important things to ask. The history is part
> of learning where we are. A lot of the detective work appears to be
> in matching the chemistry to known decay profiles...but I'm not a chemist.
>
> Anyway, incubation works for a subset of tapes, and I'm not even sure
> there is solid agreement as to why!
>
> Cheers,
>
> Richard
>
> At 12:20 AM 6/26/2006, Steven Smolian wrote:
> >There seems two stories related to sticky shed.  One or both may or
> >may not be true.
> >
> >1.  A look at the calendar discloses that sticky shed appears
> >shortly after whale oil became unavailable.  Manufacturers tried
> >various substitutes with results we all know.  The oil of the jojoba
> >bean utimately replaced whale oil and was a success.
> >
> >2.  The other was the rolling through of clean air acts
> >internationally.  I'm told there was some concordance between the
> >altering of some production processes as a result and with sticky
> >consequences.  Sticky shed appeared in specific products some
> >measurable time after the changes, which occurred in different
> >countries in different years.
> >
> >Dating these political events and matching them with known periods
> >of tape manufacture where SSS has been a result, country by country,
> >could be useful in establishing if either of the two above causes
> >are, in fact, causes.
> >
> >It seems that it does professional quality backcoated tape no harm
> >to bake it before transfer and I do so  The energy to be expended on
> >researching the roots of this problem may best be left to
> >technological historians.  I'm getting back to work.
> >
> >Steve Smolian
>
> Richard L. Hess                   email: richard@xxxxxxxxxxxxxxx
> Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
> Detailed contact information: http://www.richardhess.com/tape/contact.htm
> Quality tape transfers -- even from hard-to-play tapes.
>
>


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