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Hi Richard:

Sorry-have been out of town and haven't had a lotof time.

You're right-I shouldn't have muddied the issue by bringing PETbase 
tapes into the equation. Not sure why the A-D strips exhibited higher 
levels of acidity on the 206(which had binder hydrolysis issues). They 
were in cans, so it wasn't from the tape boxes.

Best,
--Scott


On 8/20/2013 6:01 PM, Richard L. Hess wrote:
> 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 38 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.
>