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ARSCLIST  May 2007

ARSCLIST May 2007

Subject:

Re: 'New' solution for stickey shed

From:

Jim Lindner <[log in to unmask]>

Reply-To:

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

Date:

Mon, 14 May 2007 16:02:42 -0400

Content-Type:

text/plain

Parts/Attachments:

Parts/Attachments

text/plain (242 lines)

I am attempting to re-send this message - it appears to have been  
rejected - so if you get it twice - apologies. Darn infernal digital  
technologies......



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.

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