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Tom,

The one semi interesting data point that I have is that in 2012 when I 
was at LoC, they said that they are NOT seeing the increase in baking 
time requirement that many of us on this list have noticed. I confirmed 
with them that the tapes they are transferring have been in their vaults 
for an extended period of time. They bake 8 hours and the tapes play 
fine with no residue.

So, I take that to be at least some support for the cold, dry storage 
environment that they have buried into the hillside.

Nothing scientific, just an overall impression based on a confirmed 
conversation.

Cheers,

Richard



On 12/18/2015 2:24 PM, Tom Fine wrote:
> One thing I'd like to see tested is whether these dry/cold vaults really
> make any difference with sticky-shed. I know of a vault that has Ampex
> 406 tapes, NOS, that have been stored there since the vault was built,
> either before the tapes were purchased or soon afterwards. Acting on the
> assumption that all Ampex-branded 406 is likely sticky-shed, especially
> later-era 406 (which this is), I'd love for a real-deal lab to get hold
> of one of these tapes and test if it's gone sticky. If it has, I would
> say the cold/dry vault -- which is likely NOT GOOD for acetate tapes --
> turns out to be no help to stave off sticky-shed. If the tape, or a test
> batch of tapes, are not sticky, then we have a proven data point about
> storage.
>
> My overall point is, I think there are still a lot of assumptions made
> about sticky-shed, which aren't proven and may not be true. The only
> thing that does seem to be true is that a sticky tape can be baked and
> it will playback in a mechanically successful manner. As I've said, my
> experience is that the audio deteriorates after a handful of bakes, but
> others disagree and I think we all admit we haven't done rigorous
> science on that.
>
> -- Tom Fine
>
> ----- Original Message ----- From: "Richard L. Hess"
> <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Friday, December 18, 2015 2:03 PM
> Subject: Re: [ARSCLIST] Interesting sticky-shed data point
>
>
>> Tom,
>>
>> It is harder than you think. Work has been done and continues to be
>> done on identifying, the causation, and the remediation.
>>
>> Since we have no new tape (only NOS) to play with, controlled tests
>> are practically impossible. One paper I read on potting compound
>> hydrolysis, the experimenters made new batches of the polymer to test.
>>
>> Needless to say, that is more difficult with tape, especially when we
>> have anecdotal (at least) evidence that the process control was
>> sometimes sub-optimum. And the looooong time it has been around.
>>
>> Cheers?
>>
>> Richard
>>
>>
>>
>> On 12/18/2015 8:53 AM, Tom Fine wrote:
>>> 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.
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>
>> --
>> 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.
>>
>>
>
-- 
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.