Exercising magnetic tapes

Michelle Zeccardi <mkz [at] aip__org> wrote
>I am currently writing a preservation plan for our audio/visual
>collection. I've read in the literature that audio tapes and videotapes
>should be "exercised" by playing and then rewinding.

Exercising tapes is a good idea provided it is done with good equipment
in the correct fashion.  If done with poorly adjusted equipment it is
quite easy to destroy the tape.  One might reasonably ask "Why exercise
tapes in the first place"?  The idea behind exercising tapes is to
essentially retension the pack of tape so that it does not develop
uneven tension.  It is also thought in some circles that this process
allows air to be "sandwiched" in-between the layers and allow outgassing
(although I have never seen any *real* research that talks about this).
The technical jargon goes something like ...."to minimize the possibility
of the tape taking an unwanted set due to stepped or scattered winding,
the tape should be given a continuous wind or rewind before storage"
Tape should be should be stored in a fully wound or rewound condition".
More information will be available very shortly (October-November) with
the revision of SMPTE RP103 - SMPTE recommended practice care, Storage,
Operation, Handling and Shipping of Magnetic Tape for Television.

** Real World

Often tapes are seriously damaged when people use machines that are
damaged or dirty, and if the machine doing the rewinding is not cleaned
very often, you can spread dirt and adhesive from one tape to another.
Also, the machine you use is important, don't think of using cheap
rewinders because they have no tension control and can make a major mess
of things.  My general recommendation for clients is to try to do it
once a year if possible.

    **** Moderator's comments:  See also Jim's article "Proper Care and
    Feeding of Videotape" which is available in CoOL (Gopher to
    palimpsest.stanford.edu (or via www http://palimpsest.stanford.edu/)
    and select Browse by Subject/Electronic records/Electronic storage
    media.

Jim Lindner
VidiPax
1-800-653-8434--Toll Free Help Line

                                  ***
                  Conservation DistList Instance 8:17
                Distributed: Thursday, September 1, 1994
                        Message Id: cdl-8-17-007
                                  ***