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