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.
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
> 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