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Subject: U-matic tapes and sticky shed

U-matic tapes and sticky shed

From: Jim Lindner <vidipaxjim>
Date: Wednesday, May 18, 1994
As a company specializing in the restoration of videotape, we have seen
*many* examples of 3/4" Umatic cassettes that have sticky shed syndrome,
and other unnamed problems causing heads to clog.  Attached is an
article I wrote for the Association of Moving Images newsletter which
discusses some aspects of this problem.  Please be aware that your
problems are not unique, but that immediate action is necessary on tapes
that have this problem.  Failure to act promptly may make it extremely
difficult to recover the tapes.

    Confessions of a Videotape Restorer: or How come these tapes all
    need to be cleaned differently?

    By Jim Lindner

    {This article has appeared in the most recent issue of the AMIA
    newsletter and is reproduced with permission}

    I would like to share a few of my observations that have been gained
    through restoring several hundred videotapes.  These tapes have come
    from a wide variety of sources and include many different formats
    including 1/2" reel to reel, 2" Quad, 1" Types A, B, & C, 3/4", and
    many other obsolete formats too numerous to mention (or remember).
    These tapes have been stored in a wide variety of conditions, some
    in pristine climate controlled vaults, and some in the top of
    closets in Florida or in the flooded basements of houses along the
    Long Island Sound.  All of these tapes had one thing in common:
    (they cannot be played by the user), and, perhaps most importantly,
    many things that were different.

    The scant literature on videotape degeneration primarily discusses
    binder breakdown or what has been termed the "sticky shed syndrome".
    While many of the tapes that we have restored have exhibited this
    problem to various degrees, I have come to learn that many of the
    tapes have compound problems that do not fit the "classic" profile
    of sticky shed syndrome.  In addition, while I have heard that many
    are looking for a "holy grail" solution that cures all tapes of
    their illnesses at least long enough to get a decent transfer, my
    personal observation is that such a single cure all is highly
    improbable, and that there is no one solution to the various
    maladies that have come my way.

    This realization is quite important because it means that the
    general application of a single solution "cure" can actually make
    the tapes much worse then they were before the cleaning process was
    applied.  As an obvious example, a tape that has a physical fold
    could be severely damaged by a cleaning machine that scrapes the
    surface of the tape with a razor or similar "burnishing" station.
    Similarly, baking a tape that does not have sticky shed syndrome but
    does have serious chemical contamination due to its sitting in
    contaminated water for a couple of weeks is not a good idea.  In
    fact, we have seen tapes that are of the same format, shot
    approximately at the same time, and stored next to each other
    exhibit different problems.  More often, we are greeted by
    exasperation on the part of the client when  one of two tapes that
    have been stored identically does not play when the other is fine.

    A single cure solution actually seems silly when one considers some
    of the differences in the  design of videotape itself, the
    requirements of the machines that the tapes were recorded on, and
    the handling the tape received during and after production.  As the
    technology of videotape recording changed over the years, so too did
    the characteristics of videotape, because the demands of the
    equipment required different performance on the part of the tape
    itself.  Indeed, videotape engineering is a crucial element in
    recorder design because what good is a fantastic machine without the
    tape to record the image on?  In many cases, the design of the
    recorders required radically different types of videotape
    performance, and, as a result, the chemistry of these products and
    the manufacturing techniques used to make them are very different.
    2" Quad videotape, for example had to withstand severe abuse from
    the heads every time that it was played due to the deep head
    penetration that this format required.  As a result, this tape is
    much thicker than the tape used in current digital videotape
    recorders whose heads barely touch the tape but require a much
    higher recording density than quad technology.  Optimal abrasivity
    of the tape is also different for different formats, and the
    "stiffness" of the tape which was optimal for proper head to tape
    contact in one format could be very different for another format.
    Many other characteristics of videotape vary significantly from
    format to format, and in some cases from magnetic tape supplier to

    The importance of maintaining a proper environment for tape storage
    has been discussed, but some of the worst problems  we have
    encountered are caused in production... long before storage has
    occurred.  What single restoration solution could handle the
    unintentional abuse given by a well-intentioned crew member who
    placed a tape inside a sandwich bag (that apparently previously held
    a sandwich) where it remained for 20 years?  Some of my personal
    favorites include the tape that broke in production and was taped
    together... with duct tape, and the tape that had paper "bookmarks"
    to mark where an important scene started.  And of course there have
    been tapes that have been visited by living creatures over the
    years, some microscopic, and some generally characterized as

    I have seen old quad tapes that have the problem of oxide literally
    flaking off the base, but I have never seen 1/2" reel to reel tapes
    have a severe shedding problem where the oxide literally separates
    from the base in a large section.  Similarly, I have seen 1/2" tapes
    that needed to be cleaned 8 times before the adhesive could be
    removed for playback (classic sticky shed syndrome), but I have
    never seen stickiness quite this bad with quad tapes.

    Unfortunately the end result of these videotape problems may appear
    to be the same... clogged heads which do not allow the video to be
    viewed.  Jumping to the conclusion that the malady that caused the
    clogged heads is the same problem  for different tapes is most often
    incorrect, and the theorem that one cleaning solution will work for
    all tapes is similarly incorrect.

    VidiPax provides a toll free help line
        (USA Only): 800-653-8434
        International or direct line: 212-982-5676

Jim Lindner

                  Conservation DistList Instance 7:84
                   Distributed: Sunday, May 22, 1994
                        Message Id: cdl-7-84-003
Received on Wednesday, 18 May, 1994

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