Hi, Scott,

Thanks--more good data points.

The challenge here is that the quad videotape and the 206 are both PET 
base film tapes, not acetate, so the chemistry is so different that I 
don't think we can translate. I'm not even certain how to interpret the 
readings on the A-D strips for PET tape. We did notice higher readings 
on some PVC tapes in the Mullin-Palmer project a decade more or less 
ago, and that was difficult to interpret or correlate as well. Perhaps 
the A-D strips were responding to the probably-not-acid-free IG Farben 
cardboard boxes.

Cheers,

Richard



On 2013-08-20 3:51 PM, Scott D. Smith wrote:
> Hello Richard:
>
> It was quitesome time ago that I did that project. As best as I can
> recall, the tape did not exhibit a huge amount of adhesion, but
> definitelydid not unwind by hanging free.
>
> In general, my experience has been that both 16mm and 35mm mag film
> exhibits more severe problems with VS than acetate base tapes. I have
> never encountered a tape that has shown the degree of severity we've
> seen on mag film. This probably is due in no small part to the thickness
> of the base material, combined with a thicker oxide, as well as the fact
> that many mag film have been stored (either sealed or un-sealed) in
> cans, where as tape are generally in boxes.
>
> We did one project a few years back involving both 1/2" and 1/4" 3M 206,
> some of which had been stored in cans, others in boxes. Same vault, same
> project. The 206 stored in the cans exhibited a much higher level of
> acidityon the acid strips tests.
>
> I have had varied results with cold treatment of acetate base film and
> tape. To be honest, I have never tried going down to freezing-I've just
> never been confortable with it. I have had some good success going down
> to about 38º F though. The hardest thing to control is re-acclimating it
> back to room temp without having condensation problems.
>
> I have also had good success re-hydrating both tapes and mag film, but
> have only done it in instances where the oxide is not shedding or
> de-laminating.
>
> It's tough to judge the effects of long-term exposure to dry storage
> conditions for acetate. I have seen some tapes that have done quite well
> in both dry vaults and conditions where moisture is higher. I thnk I
> would still tend to lean towards a drier environment for most materials
> though, especially if they are not in acid-free containers. I have also
> encountered a number of 2" quad tapes which were stored in a fairly high
> moisture (but cool) environment, and they did not fare well.
>
> --Scott
>
> Scott D. Smith CAS
> Chicago Audio Works, Inc.
>
>
> On 8/20/2013 11:33 AM, Richard L. Hess wrote:
>> Hi, Scott,
>>
>> Thank you for the update.
>>
>> Do you recall if the defective roll peeled off more like masking tape
>> (an exaggeration) rather than just unwinding like most tapes?
>>
>> I think the way the tape unwinds under the influence of just its own
>> weight and gravity is a good field test for layer-to-layer adhesion.
>>
>> If there was this layer-to-layer adhesion on your defective Soundcraft
>> tape, did you glean any insights into that?
>>
>> And you again confirmed the concept that acetate mag film, the "poster
>> child" for vinegar syndrome, is much worse than quarter-inch acetate
>> tape. The big open question on this for me is will acetate tapes
>> ultimately stink like the film. In other words, does the degradation
>> of 1/4 inch tape follow the same curve shape as mag film, only over a
>> longer time frame, or will the tape never reach the critical
>> threshold? This is another unstudied item.
>>
>> Two more unstudied items are:
>>
>> --Is Tom Fine's conjecture that the recommended storage conditions for
>> "tape" which appears fine-tuned for PET-film based tape harmful for
>> acetate tape by drying it out too much?
>>
>> --Is the rule in the standards to not freeze tape eliminating the
>> preservation technique which has been so good for acetate film? Or, is
>> the potential damage from freezing worse than the potential damage
>> from not freezing?
>>
>> Very interesting. Thanks again!
>>
>> Cheers,
>>
>> Richard
>>
>>
>>
>> On 2013-08-20 11:43 AM, Scott D. Smith wrote:
>>> Richard:
>>>
>>> I ran into a similar situation with some Soundcraft tapes years ago.
>>> Probably mid-fifties vintage. (Don't recall the oxide # right off hand)
>>>
>>> As I recall, I think we ended up having to hand wind most of them (this
>>> is way before we had special transports for cleaning), and cleaned and
>>> lubricated the oxide. I spoke with whoever the rep was at Soundcraft at
>>> the time, and he mentioned that he had heard of some cases of acetate
>>> tapes that had some issues with lubricant. He didn't come right out and
>>> say they were defective from the plant, but that is what I surmised from
>>> the conversation. There were other tapes from the same collectionwith
>>> the same oxide, which had no problems. I also have some tapes in my
>>> personal collection from the same era, and when I played a couple of
>>> them last year, experienced no issuesbeyond some minimal base warping.
>>>
>>> On the other hand, we have done transfers of some Soundcraft 35mm mag
>>> from the same period, and boy did it stink!
>>>
>>> --Scott
>>>
>>> Scott D. Smith CAS
>>> ChicagoAudio Works, Inc.
>>>
>>>
>>> On 8/19/2013 6:19 PM, Richard L. Hess wrote:
>>>> Hello, all,
>>>>
>>>> I have been in touch with a tape conservator who was asking about a
>>>> sticky ACETATE tape. She realizes that it should not be baked, but I
>>>> was wondering if any of you had run across this.
>>>>
>>>> The tape is in a Soundcraft box, but other tapes in Soundcraft boxes
>>>> in the same batch have transferred well. It is on a clear, six-window
>>>> reel (with three of the windows slightly larger than the other three).
>>>> It is brown oxide and not back coated.
>>>>
>>>> There are no visible signs (to the conservator) of water damage to
>>>> either the box or the reel.
>>>>
>>>> The symptoms are:
>>>>
>>>> (1) Tape sticks to underlying layer and does not drop cleanly
>>>>     off the reel
>>>> (2) No oxide appears to be pulling out at the outside
>>>> (3) When attempting to play the tape, it squeals
>>>>
>>>> The tape is half-track mono, perhaps both sides, at 3.75 in/s.
>>>>
>>>> Any and all thoughts/anecdotes would be appreciated. I may be getting
>>>> this tape to transfer and I have some ideas--I'll publish on my blog
>>>> if we have success or learn anything.
>>>>
>>>> Thanks!
>>>>
>>>> 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.
>>>>
>>>
>> 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.