LISTSERV mailing list manager LISTSERV 16.0

Help for ARSCLIST Archives


ARSCLIST Archives

ARSCLIST Archives


ARSCLIST@LISTSERV.LOC.GOV


View:

Message:

[

First

|

Previous

|

Next

|

Last

]

By Topic:

[

First

|

Previous

|

Next

|

Last

]

By Author:

[

First

|

Previous

|

Next

|

Last

]

Font:

Proportional Font

LISTSERV Archives

LISTSERV Archives

ARSCLIST Home

ARSCLIST Home

ARSCLIST  January 2016

ARSCLIST January 2016

Subject:

Re: One more sticky-shed data point - Richardson treated tape

From:

"Richard L. Hess" <[log in to unmask]>

Reply-To:

Association for Recorded Sound Discussion List <[log in to unmask]>

Date:

Tue, 26 Jan 2016 08:22:44 -0500

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (133 lines)

Hi, John,

I'm sorry, I said "deposition" to cover SSS tapes. Thanks for the 
clarification.

To further clarify, in my worldview--and I am only trying to use this 
taxonomy for the sake of clarification of failure modes and their 
treatment, Soft Binder Syndrome (SBS) is an over-arching condition and 
Sticky Shed Syndrome (SSS) is a subset with, at this point, nothing 
hanging outside the SBS representation in the Venn diagram.

While there may be degrading tapes which are not SBS, SSS tapes so far 
(with or without backcoat) are also SBS tapes. A degrading, non-SBS 
tape, for example, would be an acetate tape which is suffering from 
vinegar syndrome. It is also non-SSS.

To me, the definition of SSS is SBS that can be temporarily reversed 
through "baking" roughly following the rules of the Ampex patent, but 
allowing now for extended baking times.

The treatments that I have been discussing for almost the last decade 
(OY--has it really been that long--it was October 2006, that I presented 
the paper at the AES in San Francisco) such as D5, cold playback, and 
fast playback, are meant for tapes that normally do not respond to 
baking. I see these three methodologies overlapping to some extent 
within the SBS circle, but not overlapping with SSS, by definition.

It may be ultimately shown that those three treatments plus Marie 
O'Connell's isopropynol playback overlap to some extent, if not 
completely. I do not think that any of these four techniques overlap 
with SSS because none of them allow for the separation of the mag coat 
from the back coat when they are adhering firmly enough to pull off the 
mag coat. Those bonds seem to be broken during the baking.

This may be another validation of Peter Brothers' explanation that some 
repolymerization is occurring during the baking. I had always until now 
considered that the bonds between mag coat and back coat are broken 
during the baking cycle.

However, an alternate explanation of the process could be that the mag 
coat's internal bonds (to itself and to the base film on the proper 
side) are strengthened by the baking process to better allow the 
temporary bonds with the back coat to be broken with no ill effect. 
However, if that were the case, I would expect to still hear some 
"ripping" which I do not hear when winding a baked tape.

So that is why I have suggested that the baking process breaks the 
temporary bonds between mag coat and back coat that happen during the 
binder hydrolysis and related failure modes of SSS. I have carried on 
this bond-breaking-by-mechanical-means (thermal contraction and 
expansion) to include cold desiccation's partial success in un-pinning 
pinned, non-back-coated tapes that would suffer from mag coat pullout.

I realize we are putting a very fine point on all of this, but, 
ultimately, I think this increases our (at least my) understanding of 
the mechanism, variants, and cures for tape degradation modalities.

Cheers,

Richard



I realize that a symptom/cure-based taxonomy is less scientific than a 
cause-based taxonomy (binder hydrolysis, vinegar syndrome, etc), but it 
does have a practical application in the field for those of us 
struggling with tapes that are misbehaving. If they ain't misbehavin' 
then they don't get a classification other than, "tape" <smile>.





On 1/25/2016 9:27 PM, John Schroth wrote:
> Hi Richard:
>
> To be clear these tapes I talk about did not have back-coating and
> exhibited classic signs of sticky-shed, They quickly left large binder
> deposits on the heads when tested and responded very well to baking.
>
> These were not squealing tapes, what you have referred to in the past as
> soft binder - that needed cold play or Marie O'Connel's playback method.
> These were sticky shed tapes that did not have back-coating.
>
> My point was that we cannot ALWAYS associate sticky shed with back-coating.
>
> Kind Regards,
>
> John Schroth
> MTS
>
> On 1/24/2016 11:10 PM, Richard L. Hess wrote:
>> Hi, John,
>>
>> This is indeed true. HOWEVER, my success rate for baking tapes that
>> are suffering from squealing and/or deposition that are not back
>> coated is much lower.
>>
>> This raises another question. If all binder breakdown is hydrolysis,
>> then why doesn't baking cure it 100%? I'm thinking of Sony PR-150 and
>> 3M-175.
>>
>> These two seem to show the falling Tg, but don't have the shedding.
>> They are outliers and inconsistent.
>>
>> Cheers,
>>
>> Richard
>>
>>
>>
>> On 1/24/2016 3:41 PM, John Schroth wrote:
>>> Back-coating may instigate or speed up the hydrolysis process but I
>>> cannot ignore the fact that there are still obscure instances where the
>>> tape had no back-coating and suffered from SS. Richard, you have noted
>>> this in the past and I have had this happen in at least two instances
>>> that I can recall. I'm at home today so I don't have access to my notes,
>>> but it was clearly sticky shed on tapes that had no back-coating. So one
>>> should not "always" equate back-coating with sticky shed.
>>>
>>> Just my two cents...
>>>
>>> John Schroth
>>> MTS
>>>
>>
>
-- 
Richard L. Hess                   email: [log in to unmask]
Aurora, Ontario, Canada                             647 479 2800
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.

Top of Message | Previous Page | Permalink

Advanced Options


Options

Log In

Log In

Get Password

Get Password


Search Archives

Search Archives


Subscribe or Unsubscribe

Subscribe or Unsubscribe


Archives

November 2020
October 2020
September 2020
August 2020
July 2020
June 2020
May 2020
April 2020
March 2020
February 2020
January 2020
December 2019
November 2019
October 2019
September 2019
August 2019
July 2019
June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006
April 2006
March 2006
February 2006
January 2006
December 2005
November 2005
October 2005
September 2005
August 2005
July 2005
June 2005
May 2005
April 2005
March 2005
February 2005
January 2005
December 2004
November 2004
October 2004
September 2004
August 2004
July 2004
June 2004
May 2004
April 2004
March 2004
February 2004
January 2004
December 2003
November 2003
October 2003
September 2003
August 2003
July 2003
June 2003
May 2003
April 2003
March 2003
February 2003
January 2003

ATOM RSS1 RSS2



LISTSERV.LOC.GOV

CataList Email List Search Powered by the LISTSERV Email List Manager