I submit, then, that we don't have a clear understanding of what causes sticky-shed. Since we know 
that baking makes the tapes playable, knowing the cause may not matter at this point, but it would 
be good to close the circle. I'm surprised the government hasn't spent more time and money on 
nailing this down, given how much instrumentation and audio tape is archived. It seems like one of 
the defense-contractor labs would have the chemistry analysis and science expertise to figure this 
out. It seems to have something to do with polymer science, as I understand it. But then it may not, 
since we see that what's essentially the same material (tapes from the same batch, assumed from the 
same rolled out mass of slurry) may or may not go sticky or may not go the same amount of sticky, 
under same storage conditions.

By the way, there seems to be a similar thing with some brown-oxide acetate-backed tapes and vinegar 
syndrome. I told the tale of two Audiotape masters made around the same time, but likely from 
different batches, the A and B side masters of the MLP mono "1812 Overture." The A side tape is 
badly decayed from vinegar syndrome. It is actually a later-time tape than the B side master because 
it was mixed at the studio (music master combined with SFX master to create LP master), whereas the 
B side master is a first-generation recording, edited into a master. Both are Audiotape 
acetate-backed tapes, which have a track record of not going vinegar. So why did one go vinegar and 
one didn't? I think it's safe to assume they've been stored together all these years. My experience 
has been that Audiotape acetate-backed rarely goes vinegar, Scotch 111 variants seem to be about 
50-50 and are dependent on storage conditions, Kodak is 100%, and Irish (pre-Ampex) trends more like 
Audiotape (unlikely to go vinegar unless stored in damp conditions). So again, why? We've talked 
about different impurities in the iron oxide in any given batch. Might that also relate to 
sticky-shed, that the impurities in the iron are the actual culprit? Both conditions seem to relate 
to moisture being pulled into the tape chemistry.

Some food for thought, by real scientists. Too bad no one with that kind of expertise can get the 
time or funding to nail down the real answers.

-- Tom Fine

----- Original Message ----- 
From: "Corey Bailey" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, December 17, 2015 11:23 PM
Subject: Re: [ARSCLIST] Interesting sticky-shed data point


> Back in the day, I had a few occasions where batch numbers were not the same with bulk 1/4" (406 & 
> 456) on hubs. Tape that was on reels in boxes, when purchased in case lots, were consistent.
>
> I've also had Marie's experience with Sticky Shed where the same tape, from the same batch (Based 
> on the batch #'s from the tape ends stored with the reels), stored on the same shelf, had 
> different levels (some with none) of SS.
>
> Corey
> Corey Bailey Audio Engineering
> www.baileyzone.net
>
> On 12/17/2015 7:47 PM, Marie O'Connell wrote:
>> When I was in the States I made a largish order of about 1000 reels of
>> Emtec 911 open reel tapes.  From memory the boxes contained 20 reels per
>> box and my immediate boss liked me to record the batch number as part of my
>> workflow.  Not all the tapes in the boxes were from the same batch.
>>
>> We had a situation here where the Mitsui Gold CDR's, shrink wrapped and
>> all, not only had pit holes in them on the gold layer, but when you opened
>> the shrink-wrap and case they were full of dust!.  We sent them back but
>> heard that another institution in Asia had complained about the pit-holes
>> and sent theirs back after opening them.  It appears they were then
>> re-shrink-wrapped and we got them!
>>
>> The joys of archiving!
>>
>> Marie
>>
>> On Fri, Dec 18, 2015 at 3:54 PM, Richard L. Hess<[log in to unmask]>
>> wrote:
>>
>>
>>> Tom, what you describe is the theory. I have heard rumours that was not
>>> the case in Opelika. Cases were filled with reels when needed. I suspect
>>> that bulk packs were perhaps a bit more likely to be all the same batch.
>>>
>>> How wide were the jumbos in Opelika?
>>>
>>> Cheers,
>>>
>>> Richard
>>>
>>>
>>>
>>>
>>> On 12/17/2015 9:27 PM, Tom Fine wrote:
>>>
>>>
>>>> I thought the numbers on the box and on the stickers box indicated batch
>>>> numbers and dates of manufacture, indicating that all pancakes in the
>>>> box were from that batch and date. At least that's how I always
>>>> understood 3M and Ampex boxes.
>>>>
>>>> -- Tom Fine
>>>>
>>>> ----- Original Message ----- From: "Lou Judson"<[log in to unmask]>
>>>> To:<[log in to unmask]>
>>>> Sent: Thursday, December 17, 2015 7:54 PM
>>>> Subject: Re: [ARSCLIST] Interesting sticky-shed data point
>>>>
>>>>
>>>> Tom, is it a documented fact that all (12) rolls (reels or pancakes) of
>>>> tape in a box would be from the same manufacturing/slurry batch? I never
>>>> looked, but it would not surprise me if there were different
>>>> manufacturing runs on the same delivery carton…
>>>>
>>>> <L>
>>>> Lou Judson
>>>> Intuitive Audio
>>>> 415-883-2689
>>>>
>>>> On Dec 17, 2015, at 4:38 PM, Tom Fine<[log in to unmask]>  wrote:
>>>>
>>>> Hi Marie:
>>>>
>>>>> This is very strange:
>>>>>
>>>>>
>>>>>> I have also had reels of Ampex 456 come out of the same box of 10 or
>>>>>> 20 and
>>>>>> purchased at the same time where 1/2 have SSS and the rest are fine!
>>>>>>
>>>>>>
>>>>>>
>>>>> I've never heard of that from anyone else. That would almost seem to
>>>>> defy all theories of what causes sticky-shed, because one would assume
>>>>> by a "box" of tapes you mean a real-deal Ampex case with a batch
>>>>> number on it. If that's so, it's really freaky that some tapes in the
>>>>> same batch (which I think means the same production run of the
>>>>> chemical slurry) would get sticky-shed and others wouldn't.
>>>>>
>>>>> I'm not doubting your testimony at all, just saying that is calls into
>>>>> question what is believed to be the cause of sticky-shed, in that I
>>>>> can't see how the binder chemistry could differ within a batch.
>>>>>
>>>>>
>>>> --
>>>>
>>> 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.
>>>
>>>
>>
>
>