RICHARD HESS, YOU ARE THE MAN! Thank you for summarizing all of this in plain English!
I do very much advocate testing about whether baking degrades the sonic outcome of playback. Goran
Finberg has indicated he has taken measurements, and perhaps kept written records of those
measurements. That's certainly a start, along with Goran providing exact details of his baking and
playback methods, so others can test the results and see if they are duplicatable (I believe they
will prove to be true and repeatable, based on what I've heard with my own ears on
several-times-baked tapes). The step after that is to find out WHY. The fact that the polymers don't
re-assemble as they were when the tape was recorded may have something to do with it, I theorize. I
also theorize that something may be happening to the magnetic surface, preventing as good tape-head
contact and movement through the transport as when the tapes were pre-sticky.
We shall see about Richardson's method. I will contine to test my treated tape and will report each
time I play it. I am swabbing all surfaces for residue and noting the general performance of the
tape. I wish Richardson would be more forthcoming about his process, and we could subject his
methods to more detailed testing. To my thinking, his process holds promise and could be scaled to
become affordable, but I want to know more details in a non-NDA discussion. I think Richardson feels
he's been subjected to hostility because he's proposing something outside of the norm and something
that may disprove Ampex and 3M claims that baking "is harmless." As a "neutral party" merely
interested in what is the best thing to do with a client tape, I wish a message of welcome and
non-agenda curiosity would be transmitted to Richardson, and perhaps he'd be more open to careful
study and would share his findings in an open forum.
In general, for a tape I get in for transfer, unless I can reasonably certainly indentify it as
Scotch 206/207/208 (they are all-black, have a distinct smell, and may or may not be in a Scotch/3M
box or on a Scotch/3M reel), if it's back-coated I will bake it before playing it. To me, failure as
a transfer engineer is putting a sticky tape through a transport and having oxide stick to back-coat
and ruin the tape.
-- Tom Fine
----- Original Message -----
From: "Richard L. Hess" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, January 24, 2016 2:46 PM
Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson treated tape
> On 1/24/2016 2:05 PM, John Chester wrote:
>> On 1/24/16 1:33 PM, John Haley wrote:
>>> I have followed this long thread but frankly have found a lot of it
>>> confusing. David, I have always assumed it is in fact the black
>>> back-coating that is what has turned sticky and gums up the machine on
>>> unbaked tapes. It wouldn't be the oxide layer coming off like that.
>>
>> In my experience, which is mostly with Ampex tape, both the oxide and
>> the backcoating are sticky, and some of the oxide is coming off when an
>> unbaked tape is played. The deposit that forms on heads and guides
>> exposed to the oxide side of the tape is mostly oxide, although
>> initially it seems to be somewhat darker in color than the oxide. I
>> think some of the backcoating becomes embedded in the oxide.
>>
>> In the worst case, large chunks of oxide are so solidly attached to the
>> backcoating that they are pulled off the base. (But I've never seen
>> large chunks of backcoating pulled off the base.....)
>>
>> The deposit that forms on static surfaces exposed to the back of the
>> tape is mostly backcoating.
>
> John (Haley),
>
> John Chester's description accurately describes my experience. I think where we went with this
> thread--at least where I went--was to better understand how such different perspectives can be
> unified by better understanding what actually happens.
>
> (1) Both the mag coat and back coat are susceptible to hydrolysis.
>
> (2) The back coat is more susceptible to hydrolysis and perhaps even actively slurps up moisture
> from the air due to the large amount of carbon black in the back coat.
>
> (3) The back coat's higher moisture level directly in contact with the mag coat accelerates and
> exacerbates the hydrolysis of the mag coat.
>
> (4) Richardson's process of removing the back coat plus some added processing to re-stabilize the
> mag coat appears to be working (although I still hold to my contention that removing the back coat
> may be a risky and time-consuming process, although Richardson holds to his contention that baking
> is harmful, too).
>
> (5) Baking causes the short, sticky chains to re-polymerize into longer chains but not as long as
> the original chains.
>
> (6--Richard's next conjecture) There is contention that multiple baking cycles can degrade the
> sonic quality of a tape. What would be interesting to note is the physical scale we are talking
> about with the re-polymerization (as contrasted to wavelength) such that perhaps after several
> cycles, the magnetic domains are moved enough (at random) to start causing some gap-scatter-type
> losses (not dissimilar to azimuth losses), although in this case it is the opposite: magnetic
> domain scatter. I don't know if this is possible or if the measurement scale is correct. This is
> really a question, because if it is possible, it would neatly allow us to tie a bow around the
> theory of this process. We all look for a unified theory of everything. This is on a scale and of
> such a nature that we cannot easily observe the details.
>
> As to John Chester's comment about large chunks of mag coat coming off, it is from that experience
> that I take a very conservative approach and bake anything that looks like it might need baking. I
> had large sections of mag coat fly off in the last 1/8-inch of radius near the hub when a client
> and I agreed the tape didn't look like it needed baking. It was a rare recording of the late Stan
> Rogers live. The tape gods were with me that day...all the flying off mag coat was Stan's guitar
> introduction and we didn't miss a phrase of his singing. It was my worst experience with this. I
> will NEVER again give in to the temptation of "lets try it without baking...it doesn't look like
> it needs baking." Oh and it was on a generic empty reel in a white box and the rest of the tapes
> in the batch did not need baking.
>
> Cheers,
>
> Richard
>
> --
> 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.
>
>
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