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

[smolians@erols.com]

Heaven forbid the pancake meets with a disaster requiring the baking cure!
The absorbed moisture removed from the binder thins it.  Getting the
pancakes into the oven is no problem.  When removing them,
however, the core
will drop out.

Steve Smolian

----- Original Message -----
From: <Mick_Newnham@screensound.gov.au>
To: <AV-Media-Matters@topica.com>
Sent: Monday, June 05, 2000 9:21 AM
Subject: Re: [AV Media Matters] Re-Evaluating Tape Mastering Stock

>>Any feedback on storing as pancake vs. NAB metal reels? We have been
>thinking about storing as pancake with a micro-chamber acid free paper
>between tape pack and shipper backing as scavenger for any out gassing
>that may not have been lost in curing process. I happen to be a big fan
>of the old 3m black plastic shippers - comments on other containers for
>long term storage?<
>
>More from a storage point of view, I have recently been looking at the
>"passive" removal of decomposition by-products from film cans. One of the
>more useful references has been the Indoor Air Pollution Working Group web
>site: http://hjem.get2net.dk/ryhl/iap.htm.
>
>Of particular interest are the papers from Dr Mike Morris, University of
>Cork who has been studying the use of passive sorbents (scavengers).  In a
>1998 paper Dr Morris states "Sorbents for adsorption are inexpensive, have
>a high surface area, can normally be regenerated, and require non-toxic,
>inexpensive housing. However, it should be noted that there is no point in
>using a bed of sorbent as the kinetic energy of gases is not sufficient to
>force the gas into the sorbent unless there is a flow (positive
>pressure)."
>
>This would indicate that unless there is some form of air
>movement then the
>effectiveness of scavengers is limited.  I have yet to start looking at
>scavengers inside a system but my recent work has been looking at
>ventilating film cans and certainly the movement of air through a can
>produces substantially lower acid level in the can environment and the the
>film than even a vented can with no air movement (quite logical really).
>
>I would suggest then that adding the micro-chamber acid free paper may be
>more expense than value.
>
>Mick Newnham
>Engineering and Research Group
>Preservation and Technical Services
>ScreenSound Australia