I'm wondering if this is an extreme case of what I've been theorizing about the surface getting
degraded from going sticky and then being baked. Maybe the Sony and 3M tape that Richard has to
cold-play have a surface so screwed up, either because it goes very un-smooth or something happens
where binder material "dries out" so it doesn't shed but remains somewhat "rubbery" right at the
surface have a chemistry that makes hydrolysis particularly damaging to the physics of the material?
-- Tom Fine
----- Original Message -----
From: "Shai Drori" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, January 25, 2016 1:03 AM
Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson treated tape
> High Richard
> I think we had a discussion about these two in the past. The PR-150 has
> some batches that run fine but most do squeal. I haven't even tried baking
> them except once just for the hell of it and of course no luck. Double
> speed playback works when possible but I haven't had any lately so haven't
> tried cold play yet.
> Shai Drori
> Expert digitization services for Audio Video
> Hi Res scanning for film 8mm-35mm
> [log in to unmask]
> On Mon, Jan 25, 2016 at 6:10 AM, Richard L. Hess <[log in to unmask]>
>> 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
>> 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.
>> 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
>> Richard L. Hess email: [log in to unmask]
>> Aurora, Ontario, Canada 647 479 2800
>> Quality tape transfers -- even from hard-to-play tapes.