RE: [AV Media Matters] Containers for long-term storage ofmedia

[Peter Brothers <lists@specsbros.com>]

Scott:

There is no evidence of damaging off-gassing from polyester-base
magnetic
tape.  Granted, I don't  believe any real research has been done on the
subject- but- there is nothing in the chemical makeup of the tape to
suggest
that such off-gassing would occur.

The primary reason for not sealing up polyester-base tape is because
residual moisture can be sealed in with the tape.  The trapped moisture
can
accelerate decay under some circumstances.  If the tape is
preconditioned in
a very low humidity environment to remove moisture before sealing it up
or
if chemical desiccants are included in the container, sealing the tape
up
could actually extend its chemical stability.  This will also drive any
fungus present into dormancy, thus halting fungus based damage.
Depleting
the oxygen in the container could also be beneficial but tests on this
have
only been done over limited periods of time.

Acetate-base tape and film, on the other hand, can exhibit damaging
off-gassing.  Because of this, current consensus is that these types of
materials should not be sealed up in air-tight containers. Some people
are
having success, however, sealing film (not tape) at very low
temperatures to
retard the breakdown of the acetate.

Peter Brothers
SPECS BROS., LLC
Tape restoration and disaster recovery since 1983.
www.specsbros.com



-----Original Message-----
From: scott campbell [mailto:scottcampbell@adidam.org]
Sent: Tuesday, June 18, 2002 6:30 PM
To: AV Media Matters
Subject: [AV Media Matters] Containers for long-term storage of media


Friends,

What would be the ramifications of storing large numbers of videotape,
audiotape, data tape in fire-proof containers/safes over the longterm?
(Apart from the great expense involved). I am thinking of the 125 degree

2-hour rated type.

I have long assumed (and must have read somewhere in the past) that the
off-gassing from the media, as well as the possibility of increasing
already resident mold in older tapes, makes this proposition not good,
even detrimental, for long-term viability of tape media. Due in part to
the lack of circulation and refreshment of the air in these necessarily
air-tight containers. (I assume the same would also be true, perhaps
even more so, for film media of all types.)

Is this in fact true?

Is there any test data on this, or hard-won experiential reports among
you all or that you could point me to about this?

Can someone explain in more technical detail why doing this would or
would not be recommended.

Thanks.

Scott Campbell
Director of Archives
Eleutherian Pan-Communion of Adidam
12040 N. Seigler Road
Middletown, CA 95461
707-928-1111

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