Non-baking cure for sticky shed? (being serious for a moment)

Chuck Guzis cclist at
Mon Jan 18 13:18:37 CST 2016

On 01/18/2016 09:46 AM, Jon Elson wrote:>

> Longevity of tapes was very spotty.  Some expensive, name-brand tapes
>  just disintegrated after a few years. Others have held up amazingly
>  well.  Last year I read in some 1993 backups of my MicroVAX system
> with no trouble at all.  I did have to clean the tape head after
> every tape, but that wasn't greatly different from when the tapes
> were new.

I've not noticed that the 3M 700-series "Black Watch" tapes were any 
better or worse than other tapes of the time--if anything, they seem to 
stick less.  AFAIK, the back-coating on the 700 series was mostly a 
matter of texture, not an applied substance.

There were, however, some terrible tapes.  Scotch brand 8104 tapes are 
among the nastiest.  The tape binder often bleeds through the oxide face 
of the tape.  You can't even get the things through a cleaning machine 
without having it jam--even after several passes (the silicon carbide 
blade is scary-sharp, and the damned tape will even stick to that.) 
I've found that coating is the only way to get those tapes to make their 
way through a tape drive without halting.

Memorex tapes from the 80s (MRX IV and V) can be pretty lousy on their 
own and Memorex sold buckets of them cheaply.  Baking is pretty much 

Strangely, a crappy tape from a manufacturer doesn't mean that the same 
outfit's floppy disks are just as bad.  Wabash-branded tape is actually 
pretty decent, while Wabash-branded floppy disks are the devil's own 
spawn.  Go figure.


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