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That is very interesting. Those containers would not have been sealed so
they would have let in air - and the RH as well would be pretty constant if
the environment stayed the same. Depending on the cardboard - I can think of
a couple of things that could affect things, one would be the acidity of the
cardboard - perhaps there is a catalytic reaction with the binder. Another
is that cardboard would seem to be more permeable then plastic. I am not
sure precisely what to think about that. There has been some work in Vietnam
where they determined that by essentially "airing" the tape in controlled
conditions there was a reduction of the acetic acid in film.

It would be really nice for someone to do a controlled test and get some
real data. I know that IPI is doing some work in this area and also there is
some work going on in Prestospace in Europe. I personally am hopeful that in
the next few years we will really know what is going on - for sure.

Thanks Chris - that was very helpful.
jim

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        Jim Lindner
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        Media Matters, LLC
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        Email: [log in to unmask]
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        Address: 500 West 37th Street, 1st FL
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-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of [log in to unmask]
Sent: Monday, June 14, 2004 5:28 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Magnetic recordings tape vs. moisture

I have had specific experience with this in preserving a number of tapes
from
the 70's of the same brand, year and storage history, but different
containers.
Some were stored in original cardboard containers while others were stored
in
"archival" storage containers. In a couple of different cases I came upon
batches where the tapes stored in cardboard containers did exhibit sticky
shed,
and the tapes stored in tape care boxes did not. This was an eye opener for
me
and I did some research into it with the client. Documentation showed that
at
some point in the storage history of these tapes some were rehoused and some
were not. It wasn't clear what the policy or motivating factors were for
rehousing only parts of the collection, but the data provided as a result
was
conclusive.

Of course there are truly so many variables in the chemical and physical
makeup
of tape as well as degradation mechanisms. I don't believe you can make a
general statement that a certain set of parameters will always yield a
certain
set of results. However, my experience coupled with this data was certainly
meaningful enough to conclude that an enclosed "archival" storage container
can
greatly decrease the rate and extent of hydrolysis relative to a tape stored
in
a cardboard box.


Chris Lacinak
Director of Operations
VidiPax
450 West 31st St.
4th floor
New York, NY 10001
212-563-1999 xt. 130
[log in to unmask]


-----Original Message-----
From: James Lindner [mailto:[log in to unmask]]
Sent: Friday, June 11, 2004 12:29 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] Magnetic recordings tape vs. moisture


Years ago it was considered "good engineering practice" to keep the tapes in
the
plastic bags that they were shipped in by the manufacturer. I do not know
the
derivation of that idea - but that is what I was taught as a tape operator
in my
youth. When I got started in this field, I questioned that notion - so  I
kept
condition information about tapes that were being cleaned, and I tried to
correlate whether tapes that were in a bag were in fact in better shape. It
was
not a truly scientific study because I did not have a way to empirically
measure
how dirty tapes were in the first place, and I did have other people
cleaning
tapes then me - so what may have been slightly dirty for one person may have
been considered medium dirty for another. Nevertheless - I could not every
find
any meaningful correlation between binder degradation and tapes enclosed in
plastic bags that should have provided some level of vapor barrier
protection.
The notion that I came up with to explain this is that over long periods of
time
the RH inside the bag (unless it was sealed and virtually none were) and
outside
the bag would have equalized - and if anything the vapor barrier would have
provided a bit of latency against humidity cycling (for better or worse).
But
this was a hypothesis. In fact I could find no demonstrable correlation.

*
        Jim Lindner
*
        Media Matters, LLC
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        Email: [log in to unmask]
*
        Address: 500 West 37th Street, 1st FL
        New York, N.Y. 10018
*
        eFax (646) 349-4475
*
        Mobile: (917) 945-2662
*
        www.media-matters.net



-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]]
On Behalf Of Dave Radlauer
Sent: Friday, June 11, 2004 12:56 AM
To: [log in to unmask]
Subject: [ARSCLIST] Magnetic recordings tape vs. moisture

In a message dated 6/10/04 9:03:03 PM, [log in to unmask] writes:

<< Would a completely sealed tape box minimize sticky shed syndrome by
insulating the tape from moisture in the environment? >>

In theory . . . maybe.  When the box is closed, any ambient moisture in the
air,
and in the tape would be trapped inside.  Although dessicant (moisture
absorbing
crystals) in the box might absorb and lock-up any such moisture. But I don't
know any of the tape manufacturers really claim there "archival storage
containers" to really seal out moisture.

Dave Radlauer
www.JAZZHOT.Bigstep.com


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