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Re: [ARSCLIST] Rezerex presentation AES NYC 4/12(was Re: Baking tapes and high frequencies)
Hello, Dave,
I heard Richardson present in Austin at ARSC. I heard lots of generalities.
I think he may be on to something, and I'm trying to maintain an open mind.
Thank you for your thoughtful analysis of his presentation.
According to him, the "oxide hydrolysis" theory is a case of "common
knowledge" that we
have all accepted as fact without investigating further or re-checking the
basic scientific work that originally came up with the thesis.
It's interesting that he makes the claim, as there are several writings on
the subject that appear to be independent. The first is the Bertram paper
which Jay McKnight has kindly posted on his Web site:
http://home.flash.net/~mrltapes/bertram_humid-aging.pdf
In the ARSC presentation, Richardson dismissed the Bertram paper of
becoming too carried-away with the technical measurements.
Ampex also has a paper that I don't think was ever published: "Audio
Mastering Archive Stability" by David Anglin, Ampex Recording Media Corp.,
circa 1993. In this, he discusses an "equilibrium equation" of
[ester][water]
k(sub eq) =_______________
[acid][alcohol]
I don't know the availability of this paper.
Two of the tables from this paper appear in US Patent 5,236,790 issued Aug
17, 1993 to Medeiros et al, and assigned to Ampex Systems Corporation.
Some additional information about 3M tapes can be found
http://www.aes.org/aeshc/docs/3mtape/aorprod2.html
http://www.aes.org/aeshc/docs/3mtape/aorintr1.html
but these pages don't discuss hydrolysis, although I thought Del Eilers had
discussed it someplace.
Here are reports of Sticky Shed syndrome from the Ampex Mailing list site
http://recordist.com/ampex/docs/misc/sticky-shed.html
He claims to
have had numerous laboratory tests conducted that completely contradict the
theory of oxide binder hydrolysis and instead point to breakdown of the
backcoating as the cause of "sticky-shed" syndrome.
I would like to see these published.
claiming that baking was a
"nail in the coffin" of chemically degraded tapes.
This may be what got some people on the defensive. He is not saying, "look,
I have another (and perhaps better) way of solving this problem," but,
rather, he is telling us all we're destroying tapes by baking them.
I'm sure you saw my repost yesterday concerning the one MRL test tape that
MRL retested after baking.
The sales pitch aside
(and to be sure, I am not a chemist), I think he made a fairly good case for
his thesis.
Richardson is very caught up in his process and believes in it. This is
good. But he needs to publish at least something technical to back up his
claims. In Austin he told us "we all know heat is bad for things and
increases reaction rates, so therefore it is bad for the tapes."
My serious reservations about the Rezerex process are:
(1) It's not available
(2) It appears to be expensive
(3) It certainly is invasive, albeit in a different sense from baking
(4) It is not reversible as good conservation techniques usually are
My concern (1) is part of a general trait that we all manifest in this
business. That is that we hope and wait for something better to come along
and the promise of that sometimes causes inaction. While in some instances,
inaction is the best choice, in others, perhaps we should just get on with
it and do it.
One attendee of the
meeting even seemed to intimate that the original masters were more or less
expendable once the audio had been digitized, and that a process to preserve
reel-to-reel masters long-term was a bit of a waste of time.
While most people I know suggest that keeping the original masters is
preferred, the costs to do this are high and the benefit in some instances
may not outweigh the costs.
After all, we are on an interesting point in the curve when it comes to
reels and cassettes:
We have a downward-trending machine-quality curve. No superior playback
machines are being manufactured today for either reels or cassettes.
We have a downward-trending recording-quality curve as older recordings are
aging and suffering some degradation (minor as compared to the machines to
play them).
We have an upward-trending recording-quality curve with analog-to-digital
converters. 24/96 is commonplace.
We have a downward-trending pool of knowledge about the art and craft of
playing analog magnetic recordings.
The only glitch in these curves at the moment is Jamie Haworth's
flutter-removal system that uses bias or other constant signals present in
the recording to do audio time-base correction.
These trends suggest to me that now is as good a time as we'll ever have to
digitize these precious recordings. Ten years from now, fewer machines will
be available.
It's a complex challenge, and I appreciated Richardson's work. I just wish
it was presented in a more useable fashion so we could better evaluate it.
Cheers,
Richard
At 11:16 AM 4/13/2005, dave nolan wrote:
Hello all -
I was at the NYC AES presentation by Charles Richardson last night on his
new take on sticky-shed syndrome, and his "Rezerex" process for tape
restoration. Some basic info is available at his website:
http://www.sascom.com/rezerex/
For those unfamiliar with his work, Richardson is saying that in fact, there
is no such thing as oxide binder hydrolysis, and that the culprit is instead
breakdown of the backcoating found on most post-1970 tapes. According to
him, the "oxide hydrolysis" theory is a case of "common knowledge" that we
have all accepted as fact without investigating further or re-checking the
basic scientific work that originally came up with the thesis. He claims to
have had numerous laboratory tests conducted that completely contradict the
theory of oxide binder hydrolysis and instead point to breakdown of the
backcoating as the cause of "sticky-shed" syndrome.
He has come up with a (patented) process to chemically remove the
backcoating layer from the back of affected tapes, and to mechanically clean
the oxide side of traces of backcoating residue, restoring tapes to a
permanently playable condition (much like the pre-1970 non-backcoated mylar
tapes we have all worked with).
At times the presentation had a bit of the "sales pitch" feel to it - like
his holding up a bottle of water with a piece of tape in it to "demonstrate"
that there was no hydrolysis occurring, or his claiming that baking was a
"nail in the coffin" of chemically degraded tapes. The sales pitch aside
(and to be sure, I am not a chemist), I think he made a fairly good case for
his thesis.
It was also interesting to see a couple of folks try to poke holes in his
theory, but the major objections seemed to come from folks saying that
baking was "good enough" or "time tested", and that a new process for
preserving original masters was not desirable or necessary. To me, it
almost seemed like a couple of people were defensive about his claims that
baking tapes was destructive (perhaps because they had some part of their
reputation or business tied up in tape-baking?). One attendee of the
meeting even seemed to intimate that the original masters were more or less
expendable once the audio had been digitized, and that a process to preserve
reel-to-reel masters long-term was a bit of a waste of time.
I understand that we've all placed our eggs in the baking basket since the
solution was first suggested by Ampex, but I would have hoped that a room
full of engineers would have been more hopeful or excited about the
possibility that someone had stumbled onto a completely different (and
possibly more correct) approach to tape preservation.
Personally, I am interested in preserving original masters as long as
possible, not just as historical objects, but also in the hopes of ever
better future transfer and restoration technologies. If Richardson's
Rezerex thesis and process are indeed correct, this could be a major
breakthrough for tape preservation efforts worldwide.
The big drawback at this point is the fact that he has yet to make the
process either cost-effective or automated, as things are still in the
development stage.
I would be very interested to hear what other folks on this list have to say
about this whole Rezerex thing - from whether they think Richardson's
chemistry and physics are correct, to whether folks think that baking is
"good enough" and a new process might not be desirable irregardless of its
possible benefits.
I am just a moderately experienced tape archivist with a couple of small
projects under my belt, so I would really like to hear from folks who have
more experience in the science or the general archive/administration issues
this brings up.
dave nolan
nyc
Richard L. Hess email: richard@xxxxxxxxxxxxxxx
Vignettes
Media web: http://www.richardhess.com/tape/
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX