Re: [AV Media Matters] Detailed look at history of stickytapesyndrome

[<rohre@ARLUT.UTEXAS.EDU>]

Hi Jim,
Oh yes, Vanderwalle forces.  Yes, those can do it,  particularly in
a vacuum.

Maybe it was just coincidence that they had the same production lot
numbers as our tapes that had developed sticky shed.    When Cuddihy
called me, he was thinking he might have a batch with sticky shed.

Certainly ours had been exposed to more humidity than his, because
of our having to load the tapes into a buoy and its large battery
framework at sea on the back deck.  Its size precluded bringing it
into any sort of shipboard room. ( Needed a bigger ship we never
got.)

Examining several more cases here, have shown we have had a majority
of only back coating stiction since 787 days.   This is really good
news, as the base films and oxide binders are clearly in better,
pliable condition, and we can bake the tape to stabilize the back
coatings long enough to transfer the data to current digital media.

This set of data on 787 is pretty robust, as at that time Glen
Schulze, who made the copies, at Martin Marietta Skylab Denver
operation; experimented with emulating true I band tape signals by
overbiasing the copy station to lay down a strong magnetic
signature.

At one time, I thought we had seen the top most molecular coat of
oxide come off some tapes, while the magnetic images were retained
in deeper layers. Now, I believe, in all the cases we had seen, back
coating was coming off and moving around to the oxide side of film
because of the edge guides. I was able to see this happen on the
newer recorder we were using the other day.

We have dealt with one 7xx series tape that delaminated oxide, but
only one. We have seen a few, that predate 1971, on various 3M
media, and perhaps others.  One of those was successfully baked a
couple of years ago, stopping the delamination long enough for us to
recover the rest of the tape.

I am feeling much more confident that our older tapes are all
treatable and recoverable.

For years, I had hoped we could get a very controlled humidity
storage, but the best we have done is the double air conditioning
system we now use in the archives.  One system is the standard
building hot and cold air mixing type.  The other is local freon
based air conditioners with drain pans and condensate piped out of
the store room.  That one is run cold enough to draw down the
humidity, but it is struggle in this older building to maintain the
Ampex preferred lower humidities, since our Central air does not
have humidity control, and tends to take in outside air that follows
our climate. Much of the year we have days of 50 per cent to 60 per
cent humidity outdoors.

We are at the edge of the hill country where warm moist Gulf of
Mexico air meets colder air from the North, and rain showers develop
late in the days.

Hope you have a good trip, and be careful. Thanks for writing,
always good to hear from you.  I talked to Bob Parham at Opelika a
couple weeks ago, he sounds same as ever, but does not get to the
trade shows we used to.  The big warehouse in Opelika is up for
rent; hope Quantegy is able to hang in there for some years.

We have produced a White Paper proposing the recovery to modern
media of the archived data here, and hopefully we will get some
funding to preserve some for new research now possible with the
improved computers since this data was last processed in 1976!  We
have some contacts very interested in this, and after all, we will
only be doing what the National Archives Act requires of those
possessing Government funded data, that it be periodically reviewed
and preserved in good condition.

Some of my friends down at Kennedy Space Center got into a big data
reclamation some years ago.  They had stored old mission launch
tapes in blockhouses over on Cape Canaveral Air Force Station near
the beach, and the high marine humidity really did a number on those
tapes.  Probably like some other sites I have seen, they only had
window air conditioners in each block house, if that.  I think they
were using the same places to store tapes to be reconditioned on
their Bow cleaners/ rewinders, and constantly going in and out of
the store rooms allowed humid salt air in there on a continuing
basis.  They finally found funding support for improving storage and
handling by becoming aware of the Archives Act that requires Federal
agencies to fund proper data retention measures.  Either they were
told to do it by NASA bean counters, or maybe an auditor found the
old tapes in bad shape.  Anyway, they had a flurry of activity over
it.  Of course, now they have most things down there done by
Contractors.  We saw more and more of the NASA staffing reduced, and
things outsourced, between 1981 and 1990 or so.  Hard to find anyone
on the Cape who actually is a NASA employee anymore.

Cheers,
Stuart Rohre
Applied Research Labs UTx