I worry that below-freezing storage of acetate media may freeze-dry it out and make it so brittle
that eventually it has no plasticity. If super-cold/super-dry storage staves off severe sticky-shed
and it can be proven to really do that over time, then I would say it's the way to go on that
quantity of polyester-backed tape prone to sticky-shed (I've heard estimates of 25-33% of tapes in
vaults; I'd say it's probably closer to 25% given the long history of tape recording before
polyester back-coated tapes, the fact that not all polyester back-coated tapes develop sticky-shed,
and the fact that there is no consistent data showing that "post-sticky-shed" formulations didn't
solve the problem, and tape was used for quite a while after the problem was said to be solved).
It may well be that sticky-shed tapes need to be stored in a special way, by themselves. Much like
nitrate films (maybe even in the same vaults, because I think they both need the same storage
conditions). Everything else should probably be stored in somewhat warmer, somewhat wetter
conditions. But, we're all just speculating until there's more reliable science on this. I do speak
from decades of experience owning and using old acetate tapes, however.
-- Tom Fine
----- Original Message -----
From: "Richard L. Hess" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Sunday, March 01, 2015 10:58 AM
Subject: Re: [ARSCLIST] Distressing data point for upcoming ARSC tape playback workshop
> Hello, Tom,
> This is a wonderful post. Without actually stating this, you highlight the challenge we all face
> by NOT having adequate scientific analytical backup to help direct the care and physical
> restoration of various media. Of course, after PrestoSpace found that the same manufacturer tape
> type number could apparently represent four different formulations over time, we learned that the
> project is daunting if it is doable at all with any accuracy in an affordable manner.
> I have a couple of addenda to help round out this picture. I agree that more work needs to be
> undertaken and it is getting late to do it. I have spoken of your concerns whenever I thought it
> would make an impact as I know this is not the first time you have semi-publicly stated them here
> on ARSCList.
> (1) I believe, at least here at Library/Archives Canada, that FILM is kept cool and dry but well
> BELOW FREEZING (of water i.e. WELL BELOW 0°C / 32°F. If you want an idea about how well below, my
> GUESS is -20°C / 4°F. I also believe that this level of cold does help stave off "vinegar
> (2) When I had an informal meeting with the good folks at the Library of Congress (I think it was
> late June 2012), I started talking about the extended baking times several of us have
> independently reported and they claim that is not needed in their work. I confirmed that they are
> working with "captive" tapes from their vaults. I do think this is a clue that cold/dry storage is
> reducing the severity of sticky shed syndrome.
> I am blind copying a few people to make certain this information gets out there.
> Thanks again!
> On 2015-03-01 9:46 AM, Tom Fine ([log in to unmask]) wrote:
>> I am right now working with tapes from 1959 and 1961, 3-track 1/2"
>> tapes, with splices "replaced" in 1971 (according to documentation on
>> the boxes) and, in the case of 4 reels, splices cleaned and/or replaced
>> in the early 1990s. Alas, every splice so far has needed new cleaning
>> with Naptha and many of them -- even those cleaned and successfully
>> played in the 1990s -- have required full replacement.
>> The replacement splicing tape put on in the 1990s has proven mostly
>> stable but there has been some ooze and stiction around some splices. I
>> tend to believe that is leftover ooze from non-complete cleaning of the
>> original splices before replacement, but it could be new ooze over the
>> past 20 years.
>> Bottom line is that there seems to be no "permanent" splicing tape, it
>> all seems to ooze and/or dry out over time.
>> Another distressing datapoint ... This is the second batch of late 1950s
>> Audiotape acetate-backed tape I'm dealing with that has become very
>> brittle, like most of the plasticity has dried out of the backing. I
>> suspect this is made worse by over-dry storage conditions intended to
>> somehow "prevent" or "mitigate" sticky-shed in later tapes (and remember
>> that there is no proof that dry storage does either). I wish some
>> scientists would do some chemistry on acetate tapes and come up with
>> better storage recommendations. There are millions of acetate tapes and
>> films being stored under the same "keep it super-dry and cold" mandates
>> that are imposed on polyester media (and these conditions DON'T stave
>> off sticky-shed and DON'T make sticky tapes play longer after baking --
>> all credible research and experience so far shows that ALL tapes prone
>> to sticky-shed go sticky on their own, that baking allows playback, and
>> that ALL sticky-shed tapes go back sticky a certain time length after
>> baking; the only exceptions might be -- still not widely tried or proven
>> -- the Richardson method of chemically removing the back-coating).
>> Incredibly, these old tapes still sound damn good on playback, and are
>> able to move through a tape transport correctly after the splices are
>> cleaned and repaired. I don't know if this will be the case at some
>> future date. Luckily, these tapes I'm working with are backed by funding
>> for Plangent Process high-resolution transfers and defluttering, so the
>> resulting digital assets will be very high quality.
>> My recommendations, based on this experience:
>> 1. I've now cleaned enough gooey splices with Naptha to be convinced
>> that it is effective and safe for this job.Note that many hardware
>> stores carry a can or two or no Naptha at all. It doesn't seem to be
>> widely used by professional painters anymore.
>> 2. It's been helpful to carefully detach the reel flanges -- while the
>> tape end is taped down to the adjoining layers and the reel is not
>> loose-wound -- and carefully (on a flat surface) clean all visible
>> splice ooze (bubbles and chunks of white goo) with Naptha. I put the
>> flange back on and flip the reel over very carefully, then do the same
>> on the other side. Sometimes -- not always -- this mitigates stiction
>> between layers around the splice, preventing even slight oxide damage on
>> the edges.
>> 3. It is important to inspect the layers before and after the splice,
>> and clean all residule goo off both sides of the tape.
>> 4. Very gently deal with the splice itself. It can sometimes be gently
>> coaxed up intact -- this happens about 50% of the time with original
>> splices on these tapes. When that happens, clean the splice edges and
>> center in particular, this is where the ooze will be. When the splice
>> separates, I put a good dab of Naptha on the side stuck to the
>> tape-pack, cleaning especially the center of the splice. Almost always,
>> a gentle coax with the Q-tip with them lift the splice up so it can be
>> repaired. When this doesn't happen, I used a chopstick that I whittled
>> down to a blunt but pronounced "shovel" point. No splice points mangled
>> so far with this. I then clean both sides of the splice, both sides of
>> the tape, with a good dose of Naptha. By the way, change Q-tips
>> regularly because the accumulated sticky ooze stays on the Q-Tip after
>> the Naptha evaporates. Then I repair the splice (use a high-quality, non
>> worn-out splicing block, which isn't always to acquire these days). I
>> use early 2000's vintage white-colored semi-clear splicing tape. I don't
>> at all like this newest thicker blue-colored splicing tape (which seems
>> to be the only option these days). Luckily, I have a large store of
>> old-style splicing tape.
>> 5. When playback and transfer is complete, make sure to attach the end
>> of the reel to the adjoining tape layer (if it's stored on a hub) or to
>> the reel flange with NEW and EFFECTIVELY STICKY tape. An enemy of old
>> tapes, especially acetate tapes, is storage under loose-wind conditions.
>> The acetate expands, contracts and sometimes gets vinegar syndrome. If
>> it is stored tight-wound with the end taped down, it is less likely to
>> get edge-warp.
>> 6. Under ideal archival conditions, without tight production deadlines
>> and with unlimited funding, I would say replace all old splices as SOP.
>> Under real conditions, this is not always possible. Because of that,
>> expect to go through this same procedure again if the tape is played
>> again in the future. And, given my experience with 1990s splices, I'm
>> not sure that modern splicing tape is any better about eventually oozing
>> glue or drying out.
>> 7. This probably goes without saying, but demagnetize the tape path, all
>> metal tools, and work on the splice repair on a non-magentic surface.
>> 8. It also probably goes without saying, but use Naptha in a
>> well-ventilated area. John Chester turned me onto putting in a little
>> squeeze-bottle with a needle tip and then squeezing a few drops onto a
>> Q-Tip rather than having an open container and dipping Q-Tips into that.
>> This method really keeps the fumes to a minimum in a normal-sized room.
>> I keep a low-speed fan blowing air across the tape transport to move
>> what fumes do escape away from my face.
>> -- Tom Fine
> Richard L. Hess email: [log in to unmask]
> Aurora, Ontario, Canada 647 479 2800
> Quality tape transfers -- even from hard-to-play tapes.