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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.