Hi, Andrew,
Sorry, maybe I wasn't clear. I have updated the post*:
Agfa Tapes* (updated 2012-02-26)
*Agfa PEM-526* exhibited dry shedding. See our article here
<http://richardhess.com/notes/2009/01/30/back-coat-turning-to-powder/>.
This is a totally dry dusting of powder, so it may or may not be Soft
Binder Syndrome (SBS), but we could class it as that as the particles
are not being retained well. Although a similar condition has been
reported with PEM-469, recent experience shows a different degradation
modality for PEM-469.
*Agfa PEM-468, PEM-469* There are mixed reviews on these tapes and we
have been told that most of the bad tape was recalled and transferred at
Agfa's expense. This was supposedly affecting only a half-year's worth
of batches from pre-1990. Unike Ampex/Quantegy, baking is NOT
recommended as a matter of course, based in part on our experience with
the PEM-526 and this article
<http://www.tomshardware.co.uk/forum/page-42797_32_0.html>, although the
baking temperature may have been a bit too high (60 °C) in that instance.
The author of these pages encountered two very nasty reels of one-inch
Agfa PEM 469 in 2012-02 (recorded in 1988-01) that shed a waxy
clear-to-slightly-yellow exudate from the mag coat. This waxy coating
did show some buildup, especially during fast wind, but not nearly as
much as Ampex 456.We can't call it SSS because one of the definitions of
classic SSS is that it is resolved by baking. This apparently is made
worse by baking...and I'm too chicken to try it. It should probably be
considered yet another variant of Soft Binder Syndrome (or SBS).
**
Another point of interest is that some of the mag coat was also
transferring slightly to the back coat which was then coming off on the
capstan (which presses against the back coat side of the tape). This was
a pressure transfer from the back coat to the capstan as the pinch
roller (pressing on the mag coat side) was segmented and the segments
clearly printed onto the capstan. No pressure, no mag-coat residue. This
is an A-wind machine, a Sony APR-16. It is a reverse configuration from
the Studers.
After consultation on the ARSC List and receiving replies from Marie
O'Connell in New Zealand and Corey Bailey in Los Angeles, I decided to
continue with the non-baking recommendation as there was just too much
conversation on the Web and ARSCList against baking to make me feel
comfortable.
The tape's mag coat was run over a Pellon pad in library wind and then
over a D5-soaked Pellon pad, also in library wind. D5 was generously
applied to the heads and fixed guides immediately before the transfer.
We applied about 2.5 ml (cc) of D5 to each tape. Note D5 is also known
as decamethylcyclopentasiloxane, Siloxane D5, CAS # 541-02-6, and
sometimes referred to as Cyclomethicone (generally in regards to the
product as produced by Dow Corning). It is found in many personal care
products and has recently been declared safe for the environment by the
Canadian Ministry of the Environment
<http://www.cdr-siloxaned5-bor.ca/default.asp?lang=En&n=9320DEF6-0&offset=3&toc=show#s2.1>.
The worse of the two tapes was stopped twice to re-clean the heads and
reapply D5. It is not clear to me if the slight loss of brightness was
due to reproduce or recording issues, as apparently some batches of this
tape shed when originally manufactured.
This tape has been reported stable in parts of Europe, but Ms. O'Connell
confirmed the clear-to-yellow waxy exudate and indicated that it was one
of her least favourite tapes to transfer. She reported that it did
respond to her isopropyl drip technique
<http://richardhess.com/notes/2006/03/09/wet-playing-of-reel-tapes-with-loss-of-lubricant-a-guest-article-by-marie-oconnell/>
and Mr. Bailey suggested gentle baking (about 48 °C for 24 hours) which
allowed him to have success with the tape. He also reports success with
lubricants from The Last Factory here
<http://www.baileyzone.net/analog%20tape%20diy.htm> (second to last
section).
------
Does that help? Any other questions? Thanks for identifying my lack of
clarity.
Cheers,
Richard
On 2012-02-26 5:27 PM, Andrew Hamilton wrote:
> On Feb 26, 2012, at 4:57 PM, Richard L. Hess wrote:
>> ....The author of these pages encountered two very nasty reels of
>> one-inch Agfa PEM 469 in 2012-02 (recorded in 1988-01) that shed a
>> waxy clear-to-slightly-yellow exudate from the mag coat. The mag coat
>> was also transferring slightly to the back coat which was then coming
>> off on the capstan (which presses against the back coat side of the
>> tape).
>
> Interesting mode of SBS, this dry shedding. Was the tape B-wind or
> was the mag coat actually coming off on the pinch roller?
>
>
>
--
Richard L. Hess email: [log in to unmask]
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.
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