If the tape had been constant torque wound, the outer winds would
have been less tightly pressed against each other so it's likely
adhesion and oxide loss would occur later in the wind towards the
centre of the pack.
It seems possible damage was done in the respooling before baking,
which baking was only for 4 hours. I'd be very reluctant to hydrate
such a tape. I understood that rehydrating was only applicable to
acetate tapes to temporarily restore some flexibility in the base
layer.
Tim Gillett
----- Original Message -----
From: "Association for Recorded Sound Discussion List"
<[log in to unmask]>
To:<[log in to unmask]>
Cc:
Sent:Sun, 18 Oct 2020 03:10:09 +0000
Subject:Re: [ARSCLIST] Flaking Ampex 456.
Are the flakes adhering to the previous wrap of tape, or just falling
off? Are they brittle, or can you bend them? Was the tape exhibiting
sticky shed before you baked it, or did you bake it without playing
to find that out? You mention spooling the tape onto a metal reel
before baking. When you did that did the tape wind easily, without any
flaking or stiction? It sounds to me like you may need to rehydrate
the tape rather than baking further.
-Matt Sohn On Saturday, October 17, 2020, 07:55:05 PM EDT, James
Perrett <[log in to unmask]> wrote:
Thanks for the reply Richard,
Unfortunately these are larger flakes than the typical small
particles that
I might expect to see with Ampex tape - across the whole width of the
tape
in places.
On Sat, 17 Oct 2020 at 23:14, Richard L. Hess
<[log in to unmask]>
wrote:
> Hi, James,
>
> Yes, I would bake longer.
>
> If these are tiny dust-like flakes, these come from the edge and
that
> can be damaged, especially with a loose wind. But if they are
actually
> flat pieces of mag coat, that is much different.
>
> The little dust is, I fear, part of old tape playing.
>
> Richard
>
>
> On 2020-10-17 1:03 p.m., James Perrett wrote:
> > Thanks for the replies John and Ted.
> >
> > I must admit that I usually bake for longer (usually 8 hours for
a
> quarter
> > inch tape) but I'd missed that this was an Ampex tape as all the
others
> in
> > the same consignment were Scotch 256 and I was in a bit of a
rush. I had
> > also wound it onto a metal reel direct from one spool to another
which is
> > something that I've done before with no problem.
> >
> > I'll give it a longer bake and see if that works.
> >
> >
> > On Sat, 17 Oct 2020 at 16:39, Ted Kendall <
> > [log in to unmask]> wrote:
> >
> >> Four hours isn't nearly enough these days. The backing is
pulling the
> >> oxide off. Try four days and see if it behaves.
> >>
> >> On 17/10/2020 14:17, James Perrett wrote:
> >>> I have a reel of Ampex tape which is behaving in a way that
I've not
> seen
> >>> before. After baking the oxide is now coming off in flakes
rather than
> >> as a
> >>> gummy residue which is more common. One flake every few inches
of tape.
> >>> Other Ampex tapes baked at the same time have played fine.
Fortunately
> I
> >>> realised there was a problem and stopped playing the tape
during a
> >> section
> >>> with test tones so I haven't tried playing the section with the
wanted
> >>> audio.
> >>>
> >>> I believe that the tape is 456 although I can only make out 56
on the
> box
> >>> label. It was recorded in April 1980 at a London mastering
studio. It
> was
> >>> baked for 4 hours at 55 degrees C and was allowed to cool
slowly
> >>> afterwards. I noticed that it was more loosely wound after
baking.
> >>>
> >>> Has anyone else encountered this flaking with Ampex 456 before?
Would
> >>> baking again for longer help? Is there any other way to make
this tape
> >>> playable without damaging it further?
> >>>
> >>> Many thanks,
> >>>
> >>> James.
> >>>
> >>
> >
> >
>
> --
> Richard L. Hess email:
[log in to unmask]
> Aurora, Ontario, Canada
647 479 2800
> http://www.richardhess.com/tape/contact.htm
> Track Format - Speed - Equalization - Azimuth - Noise Reduction
> Quality tape transfers -- even from hard-to-play tapes.
>
--
**********************************************************************
* James Perrett
* JRP Music Services, Hampshire, U.K.
* Audio Mastering, Restoration, Recording and Consultancy
* Phone +44 (0) 777 600 6107
* e-mail [log in to unmask]
* http://www.jrpmusic.net
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