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From: JFARRINGTON@EAGLE.WESLEYAN.EDU (Jim Farrington)
Newsgroups: rec.audio.high-end
Subject: More on tape squeals
Message-ID: <7030@uwm.edu>
Date: 17 Oct 90 13:00:36 GMT
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Cameron Paine raises some interesting points concerning the relationship
of airflow and tape conservation.  However, it is believed by most sound
archivists and conservators that tape conservation is more a matter of 
environmental control than anything else.  Temperature and humidity control
plays the single most important role in determining tape longevity (as well as 
the longevity of every other library artifact--books, scores, LPs, CDs, 
personel, etc.).  I have never heard air described as a lubricant as most 
people consider the lubricant to be a part of the manufacturing process just 
like the oxide, backing, and other components.  

Rather than suggest that the reel cutouts have anything to do with packing, it 
seems to me that it might simply be that the particular reels used are warped 
or in some respect responsible for an uneven pack.  Are your tape packs shifting
over a period of time?  If so, that leads me to believe that the environment
in which they're stored is the culprit.  (I'm not necessarily ruling out the 
possibility of cutouts contributing to the problem or solution, I'm just not 
entirely convinced.)  An uneven pack will certainly heighten the effects of 
print-through.  Periodic repacking or respooling of tape has been a recommended
practice to redistribute tension in the pack.  This is especially helpful 
where storage conditions are less than ideal (i.e. fluctuating temperature and 
humidity).

What Steve Graham had described sounded to me like that with which we asso-
ciate the loss of the whale oil-lubricant.  If it is this you can tell because
a dark, sticky substance will be left on the tape guides and heads and will
take an extra-ordinary amount of Intraclean and swabs to eliminate.  The
Pellon method is the one that most people use to get that one last pass over
the tape heads, and the one recommended by Ampex.  Yes, we do use it here
and we find it to be very effective.  Why it does what it does I do not know.
We haven't had a problem with excess oxide shedding (nor any other problems,
for that matter) when using it, but I can't say for sure that we've tried it 
with any BASF tapes.

Pellon is described as a non-woven material (the advantage being that it will 
not shed fibres).  I've not had any problems getting it in any fabric store, 
so I would assume that it's available world-wide.  If you're having problems 
finding it in Australia let me know and I'll send you a swatch via snail mail. 
It comes in different densities, and we prefer the thicker, denser versions
for most applications.

Of course, the real question concerns the tapes we're making today.  Here
it is only ten years later that we're finding out that tapes made then are
not lasting the 20-30 year life expectancy due to a manufacuting problem.
Do we know whether or not tapes made today are any better?  What about DAT?
If, or rather when, that tape breaks or dries out or whatever, how in the hell
are you ever going to splice it or run it over a piece of Pellon?  Much the
same can be said for cassettes, but since that is certainly NOT an archival
medium one assumes that recordings of significance are recorded not only on
cassette.

Jim Farrington
Music Librarian
Wesleyan University
JFARRINGTON@WESLEYAN.BITNET
jfarrington@eagle.wesleyan.edu
ALANET:  MLA.NEWS.ED

"A librarian ought not to content himself with giving the public what it
happens to want, but ought to help create a demand for what the public
needs...."  Oscar Sonneck, 1917.