From: ARSCLIST automatic digest system <LISTSERV@xxxxxxxxxxxxxxxx>
Date: November 8, 2008 12:01:02 AM EST
To: ARSCLIST@xxxxxxxxxxxxxxxx
Subject: ARSCLIST Digest - 6 Nov 2008 to 7 Nov 2008 (#2008-300)
Reply-To: Association for Recorded Sound Discussion List
<ARSCLIST@xxxxxxxxxxxxxxxx>
There are 7 messages totalling 1366 lines in this issue.
Topics of the day:
1. revisiting tape bakers (5)
2. November issue of Black Grooves
3. Reminder CFP SSA 2009
From: "Charles A. Richardson" <charlesarichardson@xxxxxxxxxxx>
Date: November 7, 2008 1:00:49 PM EST
Subject: Re: revisiting tape bakers
Hi Richard:
There has been a continuing discussion of baking as a remedy for
sticky shed contamination on magnetic tapes. List members point to
the Ampex Baking Patent as authority for baking sticky shed tapes
to enable playback. The discussion seems to assume the safety or
ignore the damage that baking does to tapes. Baking is dangerous
and much of the information about baking tapes is misleading. The
following is not just my opinion or assertion but has been
substantiated by the scientific analysis of a nationally
recognized, independent forensic chemical laboratory.
1) The baking process set out in the Ampex Patent melts the sticky
shed debris with heat energy. This stops tape
frictional squealing while the sticky shed debris remains in a
liquefied state, but the squealing returns after the debris cools
off and solidifies once more. It does not cure the underlying
chemical causes of the tape problems which return endlessly.
2) Magnetic tapes are made with complex chains of polymers. The
polymer links are extremely heat sensitive. Baking destroys the
flexibility of the tape and the binder adhesion because it damages
the links in the chemical chains. Applying heat permanently breaks
down the chain links, causes unwanted new cross linking of chemical
bond links, and creates new, unwanted chemical compounds. The tape
becomes increasingly brittle and the coatings start to flake off
the base film. Repetitive baking increases the damage to the
chemical, magnetic and physical components, and eventually destroys
the tape.
3) Sticky shed debris, liquefied by baking, collects at the tape
head gap. This debris accumulation pushes the tape oxide surface
further and further away from the tape head's surface at the
critically important head gap. This collection of debris causes a
physical and major magnetic separation loss, which, as you know,
severely reduces the ability of the tape head gap to magnetically
scan the short wave lengths of the oxide's recorded content at high
frequencies. This results in inferior mechanical, magnetic and
sonic playback performance and thereby a deficient transfer of tape
content. The playback head's high frequencies are greatly reduced,
the noise reduction system playback performance mis-tracks, and
worsens these high frequency losses. Thus the tape sound quality is
now made dull and lifeless because sticky shed debris on the head
gap magnetically attenuates proper and complete scanning of the
important high frequencies that are now greatly reduced or even
missing altogether.
4) Baking causes increased print-through.
5) Baking causes weakened magnetic fields and thus lower flux and
output signal levels.
6) Baking does not provide any "restoration" or "rejuvenation" of
binder chemicals. To the contrary, it causes progressive
and permanent damage to and destruction of the tape. A fundamental
thermal law of chemistry is that heat energy destroys
substances.
7) Baking is not a safely repeatable solution. Each time a tape
is baked, it requires higher temperatures and/or longer bake
times. Each round of baking produces worse chemical, physical,
magnetic, mechanical, and sonic results.
8) The high heat used in baking drives off by evaporation the
light weight polymers and causes the magnetic particle material
attached to them to fall off.
9) Baking the tape damages the tape's magnetic content and
seriously degrades the playback performance. People have ruined
tapes by baking them, but this is generally not admitted, possibly
because of fear of liability and potential loss of income. They
may be unaware of any other method to stop tape squealing safely
and permanently.
10) Some proponents of baking try to rationalize this dangerous
baking method by inventing a new set of terminology and
circumstances, such as "soft binder syndrome", to justify using the
baking technique to obtain a mediocre playback. I am unaware of
any scientific evidence or support by an independent laboratory for
"soft binder syndrome" as either being separate and distinct from
or a sub-set of sticky shed syndrome.
11) The accurate standardized chemical terminology is that tape
binders are inherently hygroscopic, and thus are susceptible to
hydrolysis. The only safe and highly effective method to restore
and preserve tapes suffering from hydrolysis of the binders, or
sticky shed syndrome, is to first, put the affected tapes in a
stable environment of low heat and humidity for as long as it takes
to reverse the hydrolysis reaction, and then second, safely clean
all the tape's debris from both the oxide surface without damaging
the surface, and also completely remove its chemical material
causal source, namely the deteriorated carbon black back coating.
12) Much reliance has been placed, or should I say misplaced, on
the Ampex Baking Patent. The Ampex Baking Patent is intended
solely to expedite the transfer of recorded information. The
title, "Restored magnetic recording media and method of producing
same", is inaccurate because the baking method does not take steps
to preserve the media, but only to restore temporarily a "playable
condition" in the media. It is merely a band aide fix, not a cure.
13) The 1993 Ampex Baking Patent suggests that heating tapes to
120-130 degrees Fahrenheit "does not further deteriorate the tapes"
and implies that baking a tape for prolonged periods of time is
safe. The patent does not cite scientific or chemical evidence to
back the "no further deterioration claim". Moreover, the claim
runs directly contrary to pre-existing chemical thermal laws and
1980 scientific findings that heat damages tape's magnetic content
by increasing print through levels, published in a scholarly
article written by Ampex's own staff scientist, H. Neal Bertram.
"The Print Through Phenomenon" (JAES Volume 28, Issue 10, pp.
690-705; October 1980).
14) The elevated temperatures stated in the Ampex Baking Patent,
120-130 degrees, also violates Ampex's own tape manufacture's
warranty limiting heat to not exceed 90 degrees. This chemically
abusive high baking heat radically shortens tape lifespan to a
small fraction of the time tapes can last if they are instead
stored and handled as chemical science requires. Tapes have the
ability to be reliably archival for a very long time. However, if
abused by improper storage, handling, and wrong headed restoration,
then tapes are damaged, degraded, and destroyed far ahead of their
time.
15) As you know, a patent does not confer a certification or
implication that an invention is scientifically proven to be
effective or safe. A patent is a grant from the U. S. government
(or other authority in other countries) of a right to exclude
others from making, using, or selling one's invention and also
includes the right to license others to make, use or sell it.
A patent application is only narrowly and formally reviewed to
determine whether the invention is entitled to be granted a patent
under U. S. Patent law. The most important requirement under U. S.
Patent law is that the invention be a new or useful process,
machine, manufacture, or composition of matter, or any new and
useful improvement thereof. Clearly, a patent, baking or
otherwise, is no scientific authority and no certification of safety.
16) Richardson Magnetic Tape Restoration is concerned, not just
with minimal baking type partial recovery of the magnetic content
information contained within a sticky tape, but with the long term
preservation of magnetic tapes as the primary or original source of
the all the magnetic content information on the tapes and to create
optimal playback conditions for high quality reproduction needs.
To achieve this goal, RMTR hired a nationally recognized
independent forensic chemical laboratory to test chemically and to
examine under a high power electron microscope, the sticky shed
tapes, before and after application of baking heat treatments. The
lab results showed significant deterioration of the tape after it
was heated as per the Ampex baking patent. Application of heat
treatments, the chemists concluded, accelerates even more damage
from hydrolysis, and increases the cross linking of the polymers
used in making the PET Mylar base film and binder components of the
tapes. This baking practice soon "leads to unwanted tape
destruction." The chemists also concluded that the new RMTR
process was both safe and effective for tape restoration,
preservation, and playback mastering needs.
I have a written paper that elaborates on these concepts. The
paper is available on request.
If you or any other list members have independent chemical
laboratory research that refutes these points or supports baking as
both safe and effective for the restoration and preservation of
magnetic tapes, I would appreciate seeing it.
Charles A. Richardson, RMTR LLC
On Sep 27, 2008, at 8:42 PM, Richard L. Hess wrote:
At 08:05 PM 2008-09-27, Tom Fine wrote:
I forgot if Richard has a complete list of must-bake types on his
website. If so, I'm sure he'll provide a link.
I do and your points that I snipped are important for those who
haven't heard them before.
http://richardhess.com/notes/2007/03/21/soft-binder-syndrome-and-
sticky-shed-syndrome/
Richard L. Hess email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/
contact.htm
Quality tape transfers -- even from hard-to-play tapes.
From: "joe@xxxxxxxxxxx" <jsalerno@xxxxxxxxxxxxx>
Date: November 7, 2008 1:24:00 PM EST
Subject: Re: revisiting tape bakers
I thought this was generally known. It certainly is known that
baking is a short term "fix" to enable a tape to be migrated, not a
cure. Hi freq loss has certainly been suggested if not proven.
It seems moot. If the tape is unplayable, the destruction has
already occurred.
Charles, do you offer any alternatives to baking a tape?
(I am really hoping you or someone does)
Joe Salerno
Charles A. Richardson wrote:
Hi Richard:
There has been a continuing discussion of baking as a remedy for
sticky shed contamination on magnetic tapes. List members point
to the Ampex Baking Patent as authority for baking sticky shed
tapes to enable playback. The discussion seems to assume the
safety or ignore the damage that baking does to tapes. Baking is
dangerous and much of the information about baking tapes is
misleading. The following is not just my opinion or assertion but
has been substantiated by the scientific analysis of a nationally
recognized, independent forensic chemical laboratory.
1) The baking process set out in the Ampex Patent melts the
sticky shed debris with heat energy. This stops tape
frictional squealing while the sticky shed debris remains in a
liquefied state, but the squealing returns after the debris cools
off and solidifies once more. It does not cure the underlying
chemical causes of the tape problems which return endlessly.
2) Magnetic tapes are made with complex chains of polymers. The
polymer links are extremely heat sensitive. Baking destroys the
flexibility of the tape and the binder adhesion because it damages
the links in the chemical chains. Applying heat permanently
breaks down the chain links, causes unwanted new cross linking of
chemical bond links, and creates new, unwanted chemical
compounds. The tape becomes increasingly brittle and the coatings
start to flake off the base film. Repetitive baking increases the
damage to the chemical, magnetic and physical components, and
eventually destroys the tape.
3) Sticky shed debris, liquefied by baking, collects at the tape
head gap. This debris accumulation pushes the tape oxide surface
further and further away from the tape head's surface at the
critically important head gap. This collection of debris causes a
physical and major magnetic separation loss, which, as you know,
severely reduces the ability of the tape head gap to magnetically
scan the short wave lengths of the oxide's recorded content at
high frequencies. This results in inferior mechanical, magnetic
and sonic playback performance and thereby a deficient transfer of
tape content. The playback head's high frequencies are greatly
reduced, the noise reduction system playback performance mis-
tracks, and worsens these high frequency losses. Thus the tape
sound quality is now made dull and lifeless because sticky shed
debris on the head gap magnetically attenuates proper and complete
scanning of the important high frequencies that are now greatly
reduced or even missing altogether.
4) Baking causes increased print-through.
5) Baking causes weakened magnetic fields and thus lower flux and
output signal levels.
6) Baking does not provide any "restoration" or "rejuvenation" of
binder chemicals. To the contrary, it causes progressive
and permanent damage to and destruction of the tape. A
fundamental thermal law of chemistry is that heat energy destroys
substances.
7) Baking is not a safely repeatable solution. Each time a tape
is baked, it requires higher temperatures and/or longer bake
times. Each round of baking produces worse chemical, physical,
magnetic, mechanical, and sonic results.
8) The high heat used in baking drives off by evaporation the
light weight polymers and causes the magnetic particle material
attached to them to fall off.
9) Baking the tape damages the tape's magnetic content and
seriously degrades the playback performance. People have ruined
tapes by baking them, but this is generally not admitted, possibly
because of fear of liability and potential loss of income. They
may be unaware of any other method to stop tape squealing safely
and permanently.
10) Some proponents of baking try to rationalize this dangerous
baking method by inventing a new set of terminology and
circumstances, such as "soft binder syndrome", to justify using
the baking technique to obtain a mediocre playback. I am unaware
of any scientific evidence or support by an independent laboratory
for "soft binder syndrome" as either being separate and distinct
from or a sub-set of sticky shed syndrome.
11) The accurate standardized chemical terminology is that tape
binders are inherently hygroscopic, and thus are susceptible to
hydrolysis. The only safe and highly effective method to restore
and preserve tapes suffering from hydrolysis of the binders, or
sticky shed syndrome, is to first, put the affected tapes in a
stable environment of low heat and humidity for as long as it
takes to reverse the hydrolysis reaction, and then second, safely
clean all the tape's debris from both the oxide surface without
damaging the surface, and also completely remove its chemical
material causal source, namely the deteriorated carbon black back
coating.
12) Much reliance has been placed, or should I say misplaced, on
the Ampex Baking Patent. The Ampex Baking Patent is intended
solely to expedite the transfer of recorded information. The
title, "Restored magnetic recording media and method of producing
same", is inaccurate because the baking method does not take
steps to preserve the media, but only to restore temporarily a
"playable condition" in the media. It is merely a band aide fix,
not a cure.
13) The 1993 Ampex Baking Patent suggests that heating tapes to
120-130 degrees Fahrenheit "does not further deteriorate the
tapes" and implies that baking a tape for prolonged periods of
time is safe. The patent does not cite scientific or chemical
evidence to back the "no further deterioration claim". Moreover,
the claim runs directly contrary to pre-existing chemical thermal
laws and 1980 scientific findings that heat damages tape's
magnetic content by increasing print through levels, published in
a scholarly article written by Ampex's own staff scientist, H.
Neal Bertram. "The Print Through Phenomenon" (JAES Volume 28,
Issue 10, pp.690-705; October 1980).
14) The elevated temperatures stated in the Ampex Baking Patent,
120-130 degrees, also violates Ampex's own tape manufacture's
warranty limiting heat to not exceed 90 degrees. This chemically
abusive high baking heat radically shortens tape lifespan to a
small fraction of the time tapes can last if they are instead
stored and handled as chemical science requires. Tapes have the
ability to be reliably archival for a very long time. However, if
abused by improper storage, handling, and wrong headed
restoration, then tapes are damaged, degraded, and destroyed far
ahead of their time.
15) As you know, a patent does not confer a certification or
implication that an invention is scientifically proven to be
effective or safe. A patent is a grant from the U. S. government
(or other authority in other countries) of a right to exclude
others from making, using, or selling one's invention and also
includes the right to license others to make, use or sell it.
A patent application is only narrowly and formally reviewed to
determine whether the invention is entitled to be granted a patent
under U. S. Patent law. The most important requirement under U.
S. Patent law is that the invention be a new or useful process,
machine, manufacture, or composition of matter, or any new and
useful improvement thereof. Clearly, a patent, baking or
otherwise, is no scientific authority and no certification of safety.
16) Richardson Magnetic Tape Restoration is concerned, not just
with minimal baking type partial recovery of the magnetic content
information contained within a sticky tape, but with the long term
preservation of magnetic tapes as the primary or original source
of the all the magnetic content information on the tapes and to
create optimal playback conditions for high quality reproduction
needs. To achieve this goal, RMTR hired a nationally recognized
independent forensic chemical laboratory to test chemically and to
examine under a high power electron microscope, the sticky shed
tapes, before and after application of baking heat treatments.
The lab results showed significant deterioration of the tape after
it was heated as per the Ampex baking patent. Application of heat
treatments, the chemists concluded, accelerates even more damage
from hydrolysis, and increases the cross linking of the polymers
used in making the PET Mylar base film and binder components of
the tapes. This baking practice soon "leads to unwanted tape
destruction." The chemists also concluded that the new RMTR
process was both safe and effective for tape restoration,
preservation, and playback mastering needs.
I have a written paper that elaborates on these concepts. The
paper is available on request.
If you or any other list members have independent chemical
laboratory research that refutes these points or supports baking
as both safe and effective for the restoration and preservation of
magnetic tapes, I would appreciate seeing it.
Charles A. Richardson, RMTR LLC
On Sep 27, 2008, at 8:42 PM, Richard L. Hess wrote:
At 08:05 PM 2008-09-27, Tom Fine wrote:
I forgot if Richard has a complete list of must-bake types on
his website. If so, I'm sure he'll provide a link.
I do and your points that I snipped are important for those who
haven't heard them before.
http://richardhess.com/notes/2007/03/21/soft-binder-syndrome-and-
sticky-shed-syndrome/
Richard L. Hess email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/
contact.htm
Quality tape transfers -- even from hard-to-play tapes.
From: "Warren, Richard" <richard.warren@xxxxxxxx>
Date: November 7, 2008 1:38:16 PM EST
Subject: Re: revisiting tape bakers
Hello ARSC Folks,
I've always understood that the ARSClist is not to be used for
advertising, but here we have a really long advertisement by Mr.
Richardson, which came addressed to me as "Hi Richard" (I don't
believe I've met Mr. R.), and his reason for that salutation is not
clear. I don't work for or receive any sort of compensation from
Ampex and never have.
Mr. R. seems to be bashing Ampex for tape baking: something which I
don't recall their ever suggesting was a cure for sticky shed but
only a method for helping such tapes' contents to be played once or
twice to be copied for preservation. In fact the people at Ampex,
when sticky shed was first discovered (I seem to have the dubious
distinction of being called the "inventor" of sticky shed since
apparently it was first discovered here at Yale HSR), first
suggested other methods of dealing with the problems. These
methods, which are difficult to use and by no means perfect but
which at least do not involve heating, and another method developed
by Dick Burns of Packburn fame, are all that have been used in HSR.
They don't "cure" the problem but simply allow for playback of
problematic tapes without sticking and squealing.
If Mr. Richardson has scientific data on sticky shed, it would be
helpful if he'd submit these data and/or his paper, preferably
without the self-promotion, to the ARSC Journal for the audio
archive community's benefit. I don't see any real news in Mr. R's
long message and am rather sorry I had to slog through it.
Sincerely, Richard
-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx] On Behalf Of Charles A. Richardson
Sent: Friday, November 07, 2008 1:01 PM
To: ARSCLIST@xxxxxxxxxxxx
Subject: Re: [ARSCLIST] revisiting tape bakers
Hi Richard:
There has been a continuing discussion of baking as a remedy for
sticky shed contamination on magnetic tapes. List members point to
the Ampex Baking Patent as authority for baking sticky shed tapes to
enable playback. The discussion seems to assume the safety or ignore
the damage that baking does to tapes. Baking is dangerous and much of
the information about baking tapes is misleading. The following is
not just my opinion or assertion but has been substantiated by the
scientific analysis of a nationally recognized, independent forensic
chemical laboratory.
1) The baking process set out in the Ampex Patent melts the sticky
shed debris with heat energy. This stops tape
frictional squealing while the sticky shed debris remains in a
liquefied state, but the squealing returns after the debris cools off
and solidifies once more. It does not cure the underlying chemical
causes of the tape problems which return endlessly.
2) Magnetic tapes are made with complex chains of polymers. The
polymer links are extremely heat sensitive. Baking destroys the
flexibility of the tape and the binder adhesion because it damages the
links in the chemical chains. Applying heat permanently breaks down
the chain links, causes unwanted new cross linking of chemical bond
links, and creates new, unwanted chemical compounds. The tape becomes
increasingly brittle and the coatings start to flake off the base
film. Repetitive baking increases the damage to the chemical,
magnetic and physical components, and eventually destroys the tape.
3) Sticky shed debris, liquefied by baking, collects at the tape head
gap. This debris accumulation pushes the tape oxide surface further
and further away from the tape head's surface at the critically
important head gap. This collection of debris causes a physical and
major magnetic separation loss, which, as you know, severely reduces
the ability of the tape head gap to magnetically scan the short wave
lengths of the oxide's recorded content at high frequencies. This
results in inferior mechanical, magnetic and sonic playback
performance and thereby a deficient transfer of tape content. The
playback head's high frequencies are greatly reduced, the noise
reduction system playback performance mis-tracks, and worsens these
high frequency losses. Thus the tape sound quality is now made dull
and lifeless because sticky shed debris on the head gap magnetically
attenuates proper and complete scanning of the important high
frequencies that are now greatly reduced or even missing altogether.
4) Baking causes increased print-through.
5) Baking causes weakened magnetic fields and thus lower flux and
output signal levels.
6) Baking does not provide any "restoration" or "rejuvenation" of
binder chemicals. To the contrary, it causes progressive
and permanent damage to and destruction of the tape. A fundamental
thermal law of chemistry is that heat energy destroys
substances.
7) Baking is not a safely repeatable solution. Each time a tape is
baked, it requires higher temperatures and/or longer bake times. Each
round of baking produces worse chemical, physical, magnetic,
mechanical, and sonic results.
8) The high heat used in baking drives off by evaporation the light
weight polymers and causes the magnetic particle material attached to
them to fall off.
9) Baking the tape damages the tape's magnetic content and seriously
degrades the playback performance. People have ruined tapes by baking
them, but this is generally not admitted, possibly because of fear of
liability and potential loss of income. They may be unaware of any
other method to stop tape squealing safely and permanently.
10) Some proponents of baking try to rationalize this dangerous
baking method by inventing a new set of terminology and
circumstances, such as "soft binder syndrome", to justify using the
baking technique to obtain a mediocre playback. I am unaware of any
scientific evidence or support by an independent laboratory for "soft
binder syndrome" as either being separate and distinct from or a sub-
set of sticky shed syndrome.
11) The accurate standardized chemical terminology is that tape
binders are inherently hygroscopic, and thus are susceptible to
hydrolysis. The only safe and highly effective method to restore and
preserve tapes suffering from hydrolysis of the binders, or sticky
shed syndrome, is to first, put the affected tapes in a stable
environment of low heat and humidity for as long as it takes to
reverse the hydrolysis reaction, and then second, safely clean all
the tape's debris from both the oxide surface without damaging the
surface, and also completely remove its chemical material causal
source, namely the deteriorated carbon black back coating.
12) Much reliance has been placed, or should I say misplaced, on the
Ampex Baking Patent. The Ampex Baking Patent is intended solely to
expedite the transfer of recorded information. The title, "Restored
magnetic recording media and method of producing same", is inaccurate
because the baking method does not take steps to preserve the media,
but only to restore temporarily a "playable condition" in the media.
It is merely a band aide fix, not a cure.
13) The 1993 Ampex Baking Patent suggests that heating tapes to
120-130 degrees Fahrenheit "does not further deteriorate the tapes"
and implies that baking a tape for prolonged periods of time is safe.
The patent does not cite scientific or chemical evidence to back the
"no further deterioration claim". Moreover, the claim runs directly
contrary to pre-existing chemical thermal laws and 1980 scientific
findings that heat damages tape's magnetic content by increasing print
through levels, published in a scholarly article written by Ampex's
own staff scientist, H. Neal Bertram. "The Print Through
Phenomenon" (JAES Volume 28, Issue 10, pp.690-705; October 1980).
14) The elevated temperatures stated in the Ampex Baking Patent,
120-130 degrees, also violates Ampex's own tape manufacture's warranty
limiting heat to not exceed 90 degrees. This chemically abusive high
baking heat radically shortens tape lifespan to a small fraction of
the time tapes can last if they are instead stored and handled as
chemical science requires. Tapes have the ability to be reliably
archival for a very long time. However, if abused by improper
storage, handling, and wrong headed restoration, then tapes are
damaged, degraded, and destroyed far ahead of their time.
15) As you know, a patent does not confer a certification or
implication that an invention is scientifically proven to be effective
or safe. A patent is a grant from the U. S. government (or other
authority in other countries) of a right to exclude others from
making, using, or selling one's invention and also includes the right
to license others to make, use or sell it.
A patent application is only narrowly and formally reviewed to
determine whether the invention is entitled to be granted a patent
under U. S. Patent law. The most important requirement under U. S.
Patent law is that the invention be a new or useful process, machine,
manufacture, or composition of matter, or any new and useful
improvement thereof. Clearly, a patent, baking or otherwise, is no
scientific authority and no certification of safety.
16) Richardson Magnetic Tape Restoration is concerned, not just with
minimal baking type partial recovery of the magnetic content
information contained within a sticky tape, but with the long term
preservation of magnetic tapes as the primary or original source of
the all the magnetic content information on the tapes and to create
optimal playback conditions for high quality reproduction needs. To
achieve this goal, RMTR hired a nationally recognized independent
forensic chemical laboratory to test chemically and to examine under a
high power electron microscope, the sticky shed tapes, before and
after application of baking heat treatments. The lab results showed
significant deterioration of the tape after it was heated as per the
Ampex baking patent. Application of heat treatments, the chemists
concluded, accelerates even more damage from hydrolysis, and increases
the cross linking of the polymers used in making the PET Mylar base
film and binder components of the tapes. This baking practice soon
"leads to unwanted tape destruction." The chemists also concluded
that the new RMTR process was both safe and effective for tape
restoration, preservation, and playback mastering needs.
I have a written paper that elaborates on these concepts. The paper
is available on request.
If you or any other list members have independent chemical laboratory
research that refutes these points or supports baking as both safe and
effective for the restoration and preservation of magnetic tapes, I
would appreciate seeing it.
Charles A. Richardson, RMTR LLC
On Sep 27, 2008, at 8:42 PM, Richard L. Hess wrote:
At 08:05 PM 2008-09-27, Tom Fine wrote:
I forgot if Richard has a complete list of must-bake types on his
website. If so, I'm sure he'll provide a link.
I do and your points that I snipped are important for those who
haven't heard them before.
http://richardhess.com/notes/2007/03/21/soft-binder-syndrome-and-
sticky-shed-syndrome/
Richard L. Hess email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/
contact.htm
Quality tape transfers -- even from hard-to-play tapes.
From: Michael Shoshani <mshoshani@xxxxxxxxxxxxx>
Date: November 7, 2008 2:21:07 PM EST
Subject: Re: revisiting tape bakers
On Fri, 2008-11-07 at 13:38 -0500, Warren, Richard wrote:
Hello ARSC Folks,
I've always understood that the ARSClist is not to be used for
advertising, but here we have a really long advertisement by Mr.
Richardson, which came addressed to me as "Hi Richard" (I don't
believe I've met Mr. R.)
It came to all of us with "Hi, Richard". My guess is that he was
perhaps
addressing Richard Hess, a tape-restoration expert who has been
known to
participate in tape-baking discussions here.
Michael Shoshani
Chicago
From: "Nelson-Strauss, Brenda" <bnelsons@xxxxxxxxxxx>
Date: November 7, 2008 3:08:08 PM EST
Subject: November issue of Black Grooves
The November issue of Black Grooves has now been posted at
www.blackgrooves.org<http://www.blackgrooves.org/>. In honor of the
historic election, we're featuring several politically themed
items, ranging from a recent documentary about Marcus Garvey that's
accompanied by a phenomenal reggae soundtrack, to the overtly
revolutionary rap of Peruvian-born MC Immortal Technique. Other hip
hop offerings include new releases by Kentucky's Nappy Roots and
Atlanta rapper T.I. Though it might sound like an exposé on shady
politics, the compilation More Dirty Laundry actually explores "the
soul of Black country music." Two new offerings in our ongoing
exploration of black rock include Danielia Cotton's Rare Child and
TV on the Radio's Dear Science. Wrapping up this issue are recent
releases by blues guitarist Eric Bibb, The Murrill Family of gospel
singers, jazz vocalist/bass player Esperanza Spaulding, and neo-
soul singer Rafael Saadiq.
Brenda Nelson-Strauss
Editor, Black Grooves
Archives of African American Music and Culture
Indiana University
2805 E. 10th, Suite 180
Bloomington, IN 47408
812-855-7530
bnelsons@xxxxxxxxxxx<mailto:bnelsons@xxxxxxxxxxx>
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From: "McLemore, Laura" <Laura.McLemore@xxxxxxxx>
Date: November 7, 2008 3:47:42 PM EST
Subject: Reminder CFP SSA 2009
This is going to be a great meeting. Lots of local recording
history-Murco, Jewel, and Paula, a bunch of other small labels; KWKH,
Louisiana Hayride. There have been specific requests for sessions on
sound archives, any aspect. See the SSA annual meeting website for
more
info on Shreveport, www.southwestarchivists.org and submit a proposal.
Whole sessions or single papers are welcome. LMc
Call for Papers
Society of Southwest Archivists Annual Meeting
Shreveport, Louisiana
May 20-23, 2009
Plans are well underway for the Society of Southwest Archivist's 2009
Annual Meeting in Shreveport, Louisiana. Laura McLemore and her
enthusiastic Local Arrangements Committee are planning an exciting
meeting revolving around the theme, Into the Future Full Steam Ahead!
Attendees at the Shreveport meeting will experience lots of Southern
hospitality peppered with local culture - art, music, film, and
architecture.
The 2009 SSA Program Committee invites your proposals for program
sessions. Full proposals are encouraged. Sessions are scheduled
for 90
minutes and typically include three papers though panel discussions or
other formats are also welcome. For proposals, include title and
brief
description of the session; titles and brief descriptions of each
paper;
names of session organizer and each presenter including affiliation;
address, email address and phone numbers for all. Also include
audio-visual equipment needs for the session, and whether or not
session
presenters will provide their own equipment. Individual papers may
also
be submitted with complete information included in the proposal. The
committee may form sessions based on individual papers submitted.
The deadline for session proposals is:
Monday, December 1, 2008.
Early proposals are encouraged.
Please submit all proposals online through the SSA website:
Call for Papers (electronic version):
http://southwestarchivists.org/HTML/Program.htm
<https://owa.uta.edu/exchweb/bin/redir.asp?URL=http://
southwestarchivist
s.org/HTML/Program.htm>
Session Proposal Form: http://southwestarchivists.org/HTML/cfp09.htm
Need ideas?
Architectural collections management
(including CAD)
Cartographic collections
Collaborative projects
Collections security/high profile
thefts/forgeries
Copyright
Difficult/controversial collections
Digital collections/management/
projects/preservation
Fundraising successes (other than grants)
Minimal processing implementation
Moving image archives
Music/sound collections
Outreach
Planning new facilities
Questions?
Brenda S. McClurkin, CA
Chair, 2009 SSA Program Committee
The University of Texas at Arlington
mcclurkin@xxxxxxx
phone: (817) 272-7512 fax: (817) 272-3360
"If a nation expects to be ignorant and free, in a state of
civilization, it expects what never was and never will be"--Thomas
Jefferson
"He who destroyes a good Booke, kills reason it selfe" -- John Milton
Laura Lyons McLemore, Ph.D. C.A.
William B. Wiener, Jr. Prof. of Archives and Historic Preservation
Noel Memorial Library
Louisiana State University-Shreveport
One University Place
Shreveport, LA 71115
318-797-5378
Fax 318-797-5156
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From: "Richard L. Hess" <arclists@xxxxxxxxxxxxxxx>
Date: November 7, 2008 3:52:30 PM EST
Subject: Re: revisiting tape bakers
Hello, Charles,
It is interesting that you should post all of these comments. I
would like to suggest that your understanding of this condition and
my understanding of this condition are somewhat different.
Your authority is a nationally recognized forensic laboratory. One
of my authorities is Dr. Richard Bradshaw formerly of IBM who,
among other things, unwound the Challenger instrumentation tape
after it had been on the sea floor while other experts said it
couldn't be done. Bradshaw and his lab in Tucson were responsible
for much of the basic science into understanding the fundamentals
of tape chemistry, physics, tribology, and life. Bradshaw's former
colleague, Bharat Bhushan wrote several books on the subject.
For those of you who wish to read Dr. Bradshaw's perspective on
this particular project, please jump to the end of this over-long
message.
At 01:00 PM 2008-11-07, Charles A. Richardson wrote:
Hi Richard:
There has been a continuing discussion of baking as a remedy for
sticky shed contamination on magnetic tapes. List members point to
the Ampex Baking Patent as authority for baking sticky shed tapes to
enable playback. The discussion seems to assume the safety or ignore
the damage that baking does to tapes. Baking is dangerous and
much of
the information about baking tapes is misleading. The following is
not just my opinion or assertion but has been substantiated by the
scientific analysis of a nationally recognized, independent forensic
chemical laboratory.
1) The baking process set out in the Ampex Patent melts the sticky
shed debris with heat energy. This stops tape
frictional squealing while the sticky shed debris remains in a
liquefied state, but the squealing returns after the debris cools off
and solidifies once more. It does not cure the underlying chemical
causes of the tape problems which return endlessly.
What is your evidence for this? The Bertram and Cuddihy 1982 paper
on "Humid Aging..." does describe the scission process fairly
well. I think both of us find fault with the claim that the
scission process of the bonds is a reversible process. While it may
look fine on paper, Bradshaw assures me that it just doesn't happen
that way in a filled matrix.
The melting that I mention in my paper is related to the pre-
treatment state of the tape and the conjecture that localized
heating causes the melting of the sticky shed deposits to the tape
heads and guides which is why these deposits are difficult to remove.
Brown (1980) reinforces the humidity-driven breakdown in polyester-
polyurethane systems.
2) Magnetic tapes are made with complex chains of polymers. The
polymer links are extremely heat sensitive. Baking destroys the
flexibility of the tape and the binder adhesion because it damages
the
links in the chemical chains. Applying heat permanently breaks down
the chain links, causes unwanted new cross linking of chemical bond
links, and creates new, unwanted chemical compounds. The tape
becomes
increasingly brittle and the coatings start to flake off the base
film. Repetitive baking increases the damage to the chemical,
magnetic and physical components, and eventually destroys the tape.
Actually, Brown shows that the polyester polyurethane chains are
not substantially heat sensitive but rather humidity sensitive.
While the heat applied to the tape may be above the glass
transition temperature of the binder system (especially in degraded
binders where the loss of that temperature is a symptom of the
breakdown of the binder system) it is NOT particularly close to the
glass transition temperature of the base film.
In the hundreds of tapes that have been baked, we see a hardening
of the mag coat and an apparent increase in the glass transition
temperature as the heating drives out some of the moisture that has
been retained within the mag coat matrix.
If there is re-cross-linking it is wanted, not unwanted, as that
increases the robustness of the mag coat and allows us to obtain
additional playback.
It appears that normal degradation of the tape and/or incomplete
reactions during original manufacturing is already producing these
unwanted compounds. They are already in the tape prior to baking.
As to baking damaging the magnetic characteristics, I believe we
are well below the curie temperature of the magnetic particles, so
I do not think that is an issue. I agree that multiple baking is to
be avoided, but also have successfully baked some master tapes twice.
The descriptions provided in paragraph two sound much more like
describing a tape baked at temperatures far above the recommended
temperatures in the Ampex patent or perhaps baking an acetate based
tape which is outside the scope of the Ampex patent. Baking has
been contraindicated for acetate tapes since day one.
3) Sticky shed debris, liquefied by baking, collects at the tape
head
gap. This debris accumulation pushes the tape oxide surface further
and further away from the tape head's surface at the critically
important head gap. This collection of debris causes a physical and
major magnetic separation loss, which, as you know, severely reduces
the ability of the tape head gap to magnetically scan the short wave
lengths of the oxide's recorded content at high frequencies. This
results in inferior mechanical, magnetic and sonic playback
performance and thereby a deficient transfer of tape content. The
playback head's high frequencies are greatly reduced, the noise
reduction system playback performance mis-tracks, and worsens these
high frequency losses. Thus the tape sound quality is now made dull
and lifeless because sticky shed debris on the head gap magnetically
attenuates proper and complete scanning of the important high
frequencies that are now greatly reduced or even missing altogether.
Your description of spacing loss and its increase, starting with
the second sentence is correct and in my experience precisely
correct when attempting to play a tape which has not been baked but
needs to be. My only change is that I would use the term
"wavelength" as opposed to "frequency" as the spacing loss is
related to the wavelength which, as you know, is a function of
speed and frequency.
As to the first sentence, the sticky shed debris is not liquefied
by baking which is why a cool-down period (if not in the Ampex
patent) is recommended by all proponents of baking. In addition to
the Ampex patent, 3M also has recommended similar procedures but
with a greater stress on the cool-down period.
In fact, I do agree with you, playing the tape warm right out of
the baking process is not a good idea. If the baking is done
properly (i.e. long enough at the proper temperature) there is no
debris accumulation upon playback of the treated tape.
4) Baking causes increased print-through.
I will agree with that in some circumstances, although measuring it
in a controlled environment is difficult if not impossible. Print-
through ready exists on most tapes anyway and is a function of the
different range of sensitivity to magnetization of individual
particles. The most sensitive particles are the ones that can
become remagnetized and are the target for the "skimming" function
that Studer provided in the later versions of the A820 mastering
recorder (which I do not have) that can "erase" the print through.
I will further suggest that some of the "print through" that has
become audible on improperly handled tapes subject to sticky shed
syndrome is actually binder pullouts from the mag coat bonding with
the back coat and being heard through the tape. In many cases of
advanced sticky-shed syndrome (SSS), the back-coat-to-mag-coat
adhesion is very strong resulting in substantial pullouts of the
mag coat. This is why we never wind SSS off of the reels they are
supplied on but bake them as found. Note that this includes plastic
reels. If the baking parameters are set properly, most plastic
reels will not deform.
5) Baking causes weakened magnetic fields and thus lower flux and
output signal levels.
The only study I am aware of that mentions anything in this regard
is the one done by the Australian National Archive and shows
perhaps a 0.25 dB loss at the shortest wavelengths. It was
definitely frequency dependent, but well under one decibel which is
well within the tolerances of a reel of tape end-to-end. See
comments above about curie temperature.
6) Baking does not provide any "restoration" or "rejuvenation" of
binder chemicals. To the contrary, it causes progressive
and permanent damage to and destruction of the tape. A fundamental
thermal law of chemistry is that heat energy destroys
substances.
Yes, and I believe the when we calculate the relative damage caused
by different temperatures the equations use kelvins not degrees
celsius. I have been told that if one does the math, that a single
baking cycle would take weeks off the life of the tape. There is
heat energy at room temperature. There is heat energy in the
refrigerator. There is no heat energy at absolute zero.
Baking simply allows us to obtain an excellent transfer today. We
have the technology to arbitrarily record this transfer in any
format that we wish. We need to rescue the contents from the
unstable ribbons we call magnetic tape. Magnetic tape is not a
permanent storage medium. Nothing is. The attraction of digital is
that there is no penalty for migration from one storage bucket to
another. There is a loss in each generation in copying analog
materials, but the choice is the users: copy to digital or analog,
but get the content off the decaying old tape.
As Bob Perry, (former Director of Advanced Development in the
Magnetic Tape Division of Ampex) said in a phone interview in July
2006, "If I wanted to keep it, I'd copy it if the tape was more
than 10-15-years-old."
7) Baking is not a safely repeatable solution. Each time a tape is
baked, it requires higher temperatures and/or longer bake times.
Each
round of baking produces worse chemical, physical, magnetic,
mechanical, and sonic results.
I have done it twice and the second transfer sounded better than
the first because I had obtained a superior reproducer. No...the
temperatures should NOT be increased past the highest in the Ampex
patent. Results from higher temperature baking cannot be used to
assess the damage of Ampex-patent temperature baking.
8) The high heat used in baking drives off by evaporation the light
weight polymers and causes the magnetic particle material attached to
them to fall off.
And where do these magnetic particles go? I don't see them coming
out the vent. I don't see them in a pile in the baker. I don't see
them under the tape or around/on the heads and guides. We're
talking about rust particles here, they just don't evaporate into
thin air.
9) Baking the tape damages the tape's magnetic content and seriously
degrades the playback performance. People have ruined tapes by
baking
them, but this is generally not admitted, possibly because of fear of
liability and potential loss of income. They may be unaware of any
other method to stop tape squealing safely and permanently.
Yes, many tapes have been ruined by improper treatments of all
kinds. I attempt in my forthcoming ARSC paper (an updated version
of the AES paper where we shared the dais) to detail most of the
known treatment methods. I attempt to differentiate between tapes
that are suffering from SSS and squealing tapes that are not
suffering from SSS. I see SSS as a subset of soft binder syndrome.
In this paper, I provide details on my cold playback technique
which has been validated by several other researchers. Its
application appears limited, but allows playback of certain tapes
that squeal at room temperature. My publication of this will
hopefully be adequate as "prior art" if anyone attempts to patent
the technique. If this technique helps restore a few tapes, then I
will be happy to have promulgated it.
10) Some proponents of baking try to rationalize this dangerous
baking method by inventing a new set of terminology and
circumstances, such as "soft binder syndrome", to justify using the
baking technique to obtain a mediocre playback. I am unaware of any
scientific evidence or support by an independent laboratory for "soft
binder syndrome" as either being separate and distinct from or a
sub- set of sticky shed syndrome.
That would be me. Prior to my introduction of the term Soft Binder
Syndrome (SBS) a lot of people were discussing Loss of Lubricant
(LoL). The classic tapes that were called LoL (3M 175 and Sony
PR-150) showed up in analyses to have the lubricant (~molecular
weight 500) components still in the mix, but to have a lowered
glass transition temperature (a symptom).
The taxonomy for SSS is that if it responds well to baking (as many
of the Ampex and some of the 3M tapes do) -- and I believe these
tapes are all based on varieties of BF Goodrich (at the time)
Estane polyester polyurethane binders, although similar products
from other manufacturers could have been used -- then it is SSS. If
it does not respond to baking then it is generic SBS. A subset of
SBS tapes respond to cold playback.
11) The accurate standardized chemical terminology is that tape
binders are inherently hygroscopic, and thus are susceptible to
hydrolysis. The only safe and highly effective method to restore and
preserve tapes suffering from hydrolysis of the binders, or sticky
shed syndrome, is to first, put the affected tapes in a stable
environment of low heat and humidity for as long as it takes to
reverse the hydrolysis reaction, and then second, safely clean all
the tape's debris from both the oxide surface without damaging the
surface, and also completely remove its chemical material causal
source, namely the deteriorated carbon black back coating.
The patented Resurex(tm) process! I am glad that this process now
includes the cold/dry soak as that will often (over a period of
many months) perform the required moisture removal that baking does
in a day. It is important to stabilize the binders as much as
possible before attempting separation of the back coat and the mag
coat as described above.
Since the mag coat and back coat may share the same binder
chemistry, and pure elemental carbon tends to be quite stable,
where is the evidence that the back coating is the causal material.
What is interesting is the SBS tapes which work well in low-
temperature playback (a) do not shed like SSS tapes prior to baking
and (b) are not back coated to begin with.
Off the reel cold playback does not work for traditional SSS tapes.
Long-term DRY soak (not necessarily cold) has been shown to repair
some tapes that were suffering from too-high-humidity storage. It
has not been shown to restore SSS tapes in the information (other
than yours) that I have seen.
12) Much reliance has been placed, or should I say misplaced, on the
Ampex Baking Patent. The Ampex Baking Patent is intended solely to
expedite the transfer of recorded information. The title, "Restored
magnetic recording media and method of producing same", is inaccurate
because the baking method does not take steps to preserve the media,
but only to restore temporarily a "playable condition" in the media.
It is merely a band aide fix, not a cure.
And, since tapes in general do not violate the laws of entropy, no
tape is permanent.
13) The 1993 Ampex Baking Patent suggests that heating tapes to
120-130 degrees Fahrenheit "does not further deteriorate the tapes"
and implies that baking a tape for prolonged periods of time is safe.
The patent does not cite scientific or chemical evidence to back the
"no further deterioration claim". Moreover, the claim runs directly
contrary to pre-existing chemical thermal laws and 1980 scientific
findings that heat damages tape's magnetic content by increasing
print
through levels, published in a scholarly article written by Ampex's
own staff scientist, H. Neal Bertram. "The Print Through
Phenomenon" (JAES Volume 28, Issue 10, pp.690-705; October 1980).
Bertram has, I belive, written three papers on print-through which
I am attempting to study but have not gotten through them
completely. Remember, the temperatures of the baking process are
not higher than short-term shipping excursions that can be
expected. In fact, I would suggest that operating environments even
through room ambient is in the mid-70sF might show 80-90 degrees
above the reel motors and more at the head assembly. The machine is
the heat sink in many cases.
14) The elevated temperatures stated in the Ampex Baking Patent,
120-130 degrees, also violates Ampex's own tape manufacture's
warranty
limiting heat to not exceed 90 degrees. This chemically abusive high
baking heat radically shortens tape lifespan to a small fraction of
the time tapes can last if they are instead stored and handled as
chemical science requires. Tapes have the ability to be reliably
archival for a very long time. However, if abused by improper
storage, handling, and wrong headed restoration, then tapes are
damaged, degraded, and destroyed far ahead of their time.
If tapes had the ability to be reliably archival for a very long
time we wouldn't be having this discussion. Some tapes have this
ability, but at least some tapes that are 50 years old or older are
challenged in one way or another.
15) As you know, a patent does not confer a certification or
implication that an invention is scientifically proven to be
effective
or safe. A patent is a grant from the U. S. government (or other
authority in other countries) of a right to exclude others from
making, using, or selling one's invention and also includes the right
to license others to make, use or sell it.
A patent application is only narrowly and formally reviewed to
determine whether the invention is entitled to be granted a patent
under U. S. Patent law. The most important requirement under U. S.
Patent law is that the invention be a new or useful process, machine,
manufacture, or composition of matter, or any new and useful
improvement thereof. Clearly, a patent, baking or otherwise, is no
scientific authority and no certification of safety.
I am well aware of this and it applies to 3784746 and 6797072 as well.
16) Richardson Magnetic Tape Restoration is concerned, not just with
minimal baking type partial recovery of the magnetic content
information contained within a sticky tape, but with the long term
preservation of magnetic tapes as the primary or original source of
the all the magnetic content information on the tapes and to create
optimal playback conditions for high quality reproduction needs. To
achieve this goal, RMTR hired a nationally recognized independent
forensic chemical laboratory to test chemically and to examine
under a
high power electron microscope, the sticky shed tapes, before and
after application of baking heat treatments. The lab results showed
significant deterioration of the tape after it was heated as per the
Ampex baking patent. Application of heat treatments, the chemists
concluded, accelerates even more damage from hydrolysis, and
increases
the cross linking of the polymers used in making the PET Mylar base
film and binder components of the tapes. This baking practice soon
"leads to unwanted tape destruction." The chemists also concluded
that the new RMTR process was both safe and effective for tape
restoration, preservation, and playback mastering needs.
I have a written paper that elaborates on these concepts. The paper
is available on request.
If you or any other list members have independent chemical laboratory
research that refutes these points or supports baking as both safe
and
effective for the restoration and preservation of magnetic tapes, I
would appreciate seeing it.
Suffice it to say that there are multiple tape restorers on this
list who are making EXCELLENT transfers after properly baking tapes.
When we last discussed this in April of this year on this list, I
forwarded your message at that time to Dr. Bradshaw who responded
privately to me -- with permission to use his quotes as I saw fit:
"Richardson's apparent conviction that his process would allow a
tape to then [be] archived forever is absolutely ridiculous..."
Cheers,
Richard
Richard L. Hess email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/
contact.htm
Quality tape transfers -- even from hard-to-play tapes.