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ARSCLIST  May 2007

ARSCLIST May 2007

Subject:

Re: 'New' solution for stickey shed

From:

Steven Smolian <[log in to unmask]>

Reply-To:

Association for Recorded Sound Discussion List <[log in to unmask]>

Date:

Mon, 14 May 2007 17:08:01 -0400

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (247 lines)

Nonetheless, I wouldn't dismiss this out-of-hand.  It's a clue to another 
approach.  There is surely a chemical or compound in the product that bears 
isolating and testing.

Steve Smolian

----- Original Message ----- 
From: "Jim Lindner" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, May 14, 2007 3:47 PM
Subject: Re: [ARSCLIST] 'New' solution for stickey shed


>I read the postings on the Tape Ops page and have to agree with Peter  and 
>Richrad that some of the "statements of fact" which are claimed  are not my 
>experience either - or said in another way -  there have  been many tapes 
>that are in a state that differ very substantially  with some of the all 
>encompassing statements - such as "there has  never been a documented case 
>of a non-backcoated tape having SSS".  Sorry - I have seen a bunch. It may 
>also be somewhat of a definition  issue as well. Is it SSS or is it 
>something else - without proper  chemistry testing it is hard to tell, and 
>some of those tests are  destructive anyway..... but that does not seem to 
>stop anyone from  coming up with alternative treatment approaches. There is 
>also a  patent that has been granted to someone who claims that removing 
>the  back-coating will similarly cure tapes - and the patent has some real 
>questionable statements as well. But there you have it. The biggest 
>mystery to me is why Ampex - a company  that HAS a patent on baking  and 
>one that has a history of vigorously protecting its IP has never  done 
>anything to protect its process. But that horse is long out of  the barn - 
>and I think it is in some ways beside the point.
>
> Now what I am about to say may be a bit controversial in these  hallowed 
> ARSC halls - virtual halls I suppose - but I will speak out  and hope to 
> not be accosted - or at least to not be accosted with too  much vitriol. I 
> will promise to go back to lurking after this little  squeak. (that was a 
> joke)....
>
> So here goes...
>
> In some ways I personally feel that I have "moved on" from this  entire 
> discussion - I don't think that the point any longer is to  "cure" the 
> tape forever so that it will be OK  for analog playback. I  think that a 
> shorter term more pragmatic approach - which simply said  is "get it off 
> the bad stock" is a better bet. I think that this is  particularly true in 
> Audio - unless that particular reel has some  artifactual value (i.e. it 
> was owned by someone famous and is the  only extant recording of its 
> type) - then the point is to save the  content in a fashion that is as 
> clean as possible - and move on. I  don't see that there will be a surfeit 
> of operable 2" Studer machines  100 years from now to really deal with the 
> legacy that is purported  to be saved by saving the original carrier - and 
> at some point we  need to be comfortable enough to say - yeah - we have 
> captured the  content extremely well - and well enough is likely to be 
> well  enough.... forever... because at some point it has to be. The scale 
> of the problem is SO large that any other philosophy is simply 
> unworkable, as a practical matter.
>
> We have been doing some market research into the number of tapes that 
> really are out there - and at the moment I am talking about Video  tapes. 
> I was always suspicious about the UNESCO claim of 200 million  carriers. I 
> just did not believe it - it did not make sense to me.  Doing some real 
> market research has provided some numbers that  frankly stun me - and I 
> have been in this for a LONG time - and still  I am shocked. Here is one. 
> Disney - has over 6 million tapes. One  company. 6 Million. Now I have no 
> idea how many audio tapes they have  - but it is the scale that dwarfs the 
> mind. MTV 1.5 million - that is  MILLION. One vendor alone - I can't say 
> who - sold more then 300  MILLION Umatic carriers - and that was just in 
> Europe. VHS tapes -  more then 300 million blank tapes a year (not 
> pre-recorded tapes,  blank ones) for at least 15 years. I could go on - 
> but the point is  this. As a field - of people who care about the 
> preservation of  cultural heritage.... we need to move on and come up with 
> better and  faster and cheaper ways to transfer these tapes - because if 
> we don't  - it is game over for the huge and overwhelming percentage of 
> them.  Sure - with proper storage we can extend the life- but to what end? 
> What are we waiting for - other then retirement and to pass them on  to 
> the next person. Are we expecting a new generation of really cheap  analog 
> mass migration systems to come out of the mist and magically  play back 
> the tapes on a yet undefined new format to save for  posterity - or is 
> there another reality - one decidedly less sexy and  grim - which is that 
> there is not likely to be much work in these  areas because manufacturers 
> are looking elsewhere - and what we are  saving them for - is for being 
> thrown out - by someone else - but  being thrown out nevertheless because 
> at some point - it truly is  game over -because there isnt much gear and 
> there is certainly less  time.
>
> Call this a plaintive cry to the field to stop working on stop-gap 
> thinking and work toward a more comprehensive approach to the saving  of 
> all of this content. Painting these tapes with NUFinish is really  besides 
> the point. The point is that Analog is over, and the sooner  we get to the 
> really hard job of developing cost effective mass  migration techniques to 
> save the vast corpus the better. Now some of  you may say my statements 
> are self-serving - and I will fully and  freely admit that I have worked 
> very hard to develop these techniques  and have worked to commercialize 
> them - but I do not see any other  way to save the content, and I have 
> been successful in driving the  price lower and lower using new 
> technology. But - we are just one  company - and we need help - yes we 
> need competition because THE  point is to save the content - and to do 
> that - we need to be  thinking differently. The problem is not how do we 
> stop a single  troublesome tape from squeaking - the problem is how do we 
> migrate  the millions of recordings fast enough and cost effective enough 
> and  good enough - for the future. I don't see much of that going on - and 
> it deeply concerns me. We need more people thinking this way - I want  to 
> read about techniques that can be applied to thousands of tapes  that will 
> allow fast and cost effective transfer. This is something  that we ALL 
> need to work on - the collective brains and expertise on  this list and 
> others needs to focus - we can differ in our individual  philosophies but 
> please let us not get so distracted by esoteric un- scaleable treatments, 
> that we forget the whole point. Which is - to  save the stuff. I am sad to 
> say that collectively - all of us  (including me)- have not been doing a 
> very good job - we need to do  MUCH better. We need to work together - and 
> smarter. The risk of loss  is simply too great.
>
> Ok - I am done - and I am running,,,,
>
> Jim Lindner
>
> Email: [log in to unmask]
>
>   Media Matters LLC.
>   SAMMA Systems LLC.
>   450 West 31st Street 4th Floor
>   New York, N.Y. 10001
>
> eFax (646) 349-4475
> Mobile: (917) 945-2662
> Office: (212) 268-5528
>
> www.media-matters.net
> Media Matters LLC. is a technical consultancy specializing in  archival 
> audio and video material. We provide advice and analysis, to  media 
> archives that apply the beneficial advances in technology to  collection 
> management.
>
> www.sammasystems.com
> SAMMA Systems provides tools and products that implement and optimize  the 
> advances in modern technology with established media preservation  and 
> access practices.
>
>
> On May 14, 2007, at 1:59 PM, Richard L. Hess wrote:
>
>> At 07:48 AM 2007-05-14, Tom Fine wrote:
>>> Hi Konrad:
>>>
>>> Some of what this guy says is simply not right about sticky-shed.  I 
>>> can't comment on his "cure". I'll stick with baking tapes, which  is 
>>> proven to work.
>>>
>>> I'm hoping Richard Hess posts a long missive on this one. With  this 
>>> topic well-addressed many other places, I wonder why so much  mythology 
>>> persists?
>>
>> Hello, Tom, Konrad,
>>
>> Peter Brothers has posted an excellent hypothesis as to why the  chemical 
>> technique may work. If we consider that the short (broken)  chains which 
>> is the lower molecular weight, sticky stuff ends up  partially adsorbing 
>> to the magnetic particles when water is driven  out, then this mystery 
>> chemical could also be a water "magnet" and  can pull the water out of 
>> the coating allowing sites for the short  chains to adsorb. This is 
>> consistent with the baking process.
>>
>> We certainly have seen tapes suffering from binder hydrolysis --  what 
>> I'm starting to call "Soft Binder Syndrome" (SBS). With non- back-coated 
>> tapes there is a large population (not 100%, but close)  that do not 
>> respond to baking. These are the SBS without SSS tapes.  We used to call 
>> them "loss of lubricant" (LoL) until we found out  there was still ample 
>> lubricant in the tapes.
>>
>> What we are seeing with the non-back-coated tapes that have SBS  (and 
>> squeal) is that they are in a rubbery phase at room  temperature because 
>> the breakdown of the polymers has caused the  temperature at which the 
>> surface turns from smooth to rubbery  (called the GLASS TRANSITION 
>> TEMPERATURE or Tg) has fallen to below  room temperature. What we do in 
>> these cases is play the tapes with  the tape and the player below the 
>> current Tg of the tape.
>>
>> Measuring Tg is not easy -- you need to measure the Youngs Modulus  of 
>> the Coating (alone not on the basefilm) at various temperatures  and from 
>> that plot you can extract the Tg.
>>
>> It all comes down to the tapes decaying and for all of the 
>> polyester-polyurethane tapes it appears that moisture is the  catalyst 
>> for the breakdown -- hence as Peter says, it's all hydroysis.
>>
>> Incubation/baking appears to cause enough movement in the tape pack  to 
>> break the layer-to-layer bonds that form under pressure  (especially near 
>> the hub) that causes pinning and pullouts. I have  found that slow (1.88 
>> in/s) playback of the tape also helps in that  regard.
>>
>> I think our goal here is to use reliable, tested processes and  digitize 
>> the content. I spent a substantial amount of effort  working on tapes 
>> that squealed and did not respond to baking. My  cold playing technique 
>> (which I encourage all of you to try and  respond back) should, in 
>> theory, work with SSS tape as well as SBS  (and I suggest that SSS is a 
>> subset of SBS), but the massive  amounts of debris generated by the 
>> backcoat/magcoat combination  overwhelms the capability of cold playback 
>> (at least right now) and  at pro play speeds, pullout is exacerbated due 
>> to the bonding  between backcoat and magcoat.
>>
>> I do not think we've yet seen a documented case of LoL so  thankfully 
>> that myth is being put to bed. We used to think the  squealing Sony 
>> PR-150 and 3M 175 was LoL, but we now see that it is  SBS. By the way, 
>> the Tg of one sample of 175 was about +8C or about  46F.
>>
>> Keeping polyester polyurethane tapes dry (<40% RH) is a good way to  keep 
>> them feeling OK. I had a non-backcoated tape of this type that  had been 
>> peaking at 75% RH in storage "heal" after three months  storage at about 
>> 40% RH.
>>
>> By the way, it is approximately a minute:day relationship between 
>> thermal and moisture equilibrium--or at least that's a convenient  way to 
>> think of it. In other words if a tape takes 90 minutes to  reach thermal 
>> equilibrium throughout the pack, then it takes 90  days to reach moisture 
>> equilibrium. This is based on work with 1- inch tapes so 1/4-inch tapes 
>> might not be as bad, but it seems to  match my experience.
>>
>> My AES paper cites the reference for that.
>>
>> In general, I am less happy with a chemical approach than a 
>> physical/state approach (within limits) to the SBS/SSS problem as  there 
>> is a great chance of unknown, long-term damage from any  chemical 
>> approach. With that said, I have tried approaches to SBS  based on the 
>> LoL hypothesis and they were abysmal failures.
>>
>> Konrad: we did have a belated success in your neck of the woods  with 
>> playing a tape in a fridge. Paul or Mike have the details. I  think it 
>> needed 48 hours of cold soak before it played.
>>
>> Cheers,
>>
>> Richard
>>
>>
>> Richard L. Hess                   email: [log in to unmask]
>> Aurora, Ontario, Canada       (905) 713 6733     1-877-TAPE-FIX
>> Detailed contact information: http://www.richardhess.com/tape/ 
>> contact.htm
>> Quality tape transfers -- even from hard-to-play tapes.
>
>
> -- 
> No virus found in this incoming message.
> Checked by AVG Free Edition. Version: 7.5.467 / Virus Database: 
> 269.7.0/803 - Release Date: 5/13/2007 12:17 PM
>
> 

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