6 Apr
2016
6 Apr
'16
7:36 p.m.
On 04/06/2016 06:00 PM, Paul Koning wrote:
I have no experience with this issue in floppies. But
I have a
distressingly large quantity of audio cassettes that have gone bad
over 10 or 20 years. It wasn't wear; they weren't played regularly.
Instead, something bad happened with the structure of the coating so
that they would squeak loudly when played, both over the playback and
physically (noisy passage over the head). The problem is clearly
incompetent chemical engineering, because it showed up only in one
brand, which as a result is now on my "never again" list for any of
its products.
Floppies, tapes, etc. can suffer breakdown in binder, leading to the
dreaded "sticky shed" issue, for which baking is often prescribed.
I've had half-inch tapes suffer from binder "bleed", where the sticky
stuff ends up on the oxide surface and sticks to just about *anything*,
including heads, guides, etc. Running said tape through a cleaning
machine does next to nothing, other than to cause the tape to stick to
the cleaning blade.
Short term, your friend is D5/cyclomethicone applied as a thin layer and
the tape read immedately (D5 is somewhat volatile and evaporates).
I'll emphasize that my interest is strictly in *reading* and not writing
or re-use of this stuff.
Again, my money's on binder breakdown. I have lots of samples if
someone wants to investigate further, but the audio tape guys have done
a lot of work on this.
--Chuck