Re: [AV Media Matters] Re-Evaluating Tape Mastering Stock

[rohre@ARLUT.UTEXAS.EDU]

Jim raised some other questions as to reels used to store and
pancake storage.

We have always had metal reels and glass reels for Masters.  I
like the idea
of being able to let the tape breathe, if outgassing happens.
The thing about
the acid free paper, will it take up an mositure from the tape, and then
release it back to the tape if the environment changes?  You
probably want to
store tape with a sealed shipper, and Quantegy was offering those
at one time.
You might enclose a package of silica gel to take up residual
moisture, and
preserve a dry environment near the tape.  These should be
changed when the
indicator color turns.  Some can be dried out and reused.

Hopefully, a pancake would be handled and stored carefully,
without the chance
of dropping it. (I cringe at that concept).  Yet, I have had the
misfortune to
once even have a glass reel get away and hit the floor on edge.  It has a
plastic coating that held the glass larger pieces together, and
we were able
to salvage the tape, with no apparent signal or magnetic
degradation, in spite
of the blow in earth's magnetic field, which in theory imparts
400 mGauss to
the tape, depending on its alignment with earth field lines.  (We
unreeled the
tape from the broken reel very slowly, and used a fine brush to sweep out
small glass particles, if any.  The reel held the pieces in the
plastic film
for the most part.)  Open metal reels fall and get a flange bent,
or can have
a flange crushed in shipping.  (Many of our tapes had to be
shipped in carton
lots to overseas bases).  I got pretty quick at changing flanges over the
years.  The tape again was fine in all cases.  These usually were
blanks going
to the field and would be bulk degaussed on receipt.  Masters
always came back
by courier, in Mu Metal transit cases.

We bag and seal our stored tapes, in a reel carton, in a dry lab.
 We have a
dual airconditioning system in our Master archives.  It is
manipulated to keep
the humidity in optimum lower range.  We store on metal shelves,
in metal door
cabinets.  Back up copies are stored in a Safe Site facility elsewhere.
Working copies are in another location.  We have received sticky
shed tapes at
times, and have successfully used the Ampex baking formula to
recover them for
use and transfer to new media.

Hope some of these experiences aid others with archives questions.

Stuart Rohre
Univ. of Tx., Applied Reserach Labs
A/D and Recording Facility