All this talk about 467 made me realize that 15 years ago I bought 4 reels
of 467 (half inch) as well as 4 reels of 499 (2 inch) and 4 reels of 499
(quarter inch). All this for a project that never materialized. These tapes
are still sealed but does that mean that their binder has become
problematic ? Should I simply throw them out ? I don't want to risk
ruining a session because of bad tape. Anyone else been faced with that
2012/2/8 Richard L. Hess <[log in to unmask]>
> Hi, Tom and Jim,
> This is an interesting discussion as I have had a very minor success rate
> baking an Ampex 467 DAT. I am compiling field reports of linear-track 467
> reel tape becoming problematic. I think we saw some of this about seven
> years ago with some Mitsubishi X80 tapes that appeared to have "bit
> splitter" issues, but I have suggested it might be stick-slip collapsing
> the eye pattern.
> My experience (other than 100% success rate with one DAT tape--not
> anything to base anything on) is strictly with longitudinal tapes. I think
> that Martin has a mixture of issues and from very limited experience, the
> stuff which bonded did so because it was pulled out during the un-baked
> I have baked about 8-10 reels of 1" 9600' assorted instrumentation tape on
> 14" hubs (the flanges do NOT fit in the larger American Harvest, but the
> pancakes do). They were fine.
> This is nasty and will only get nastier. I wish we had someone with deep
> pockets funding analytical labs populated by people who understood tape!
> I do appreciate both of your comments and this is a healthy debate!
> On 2012-02-08 7:22 PM, Tom Fine wrote:
>> Hi Jim:
>> I should have stated that my comments were limited to audio tape (1.5 mil
>> and 1 mil thickness). I've never messed with the thinner tapes and I don't
>> know what the consequences of any of this are with non-linear-recorded
>> tapes or information-dense formats.
>> With what Martin is describing, I can't see why baking does what he is
>> describing it doing. Do you or anyone else have some facts as to the
>> mechanism that would cause the globs to remain sticky "tar-balls"? All I
>> can think is, they are globs of concentrated goo that can't be baked back
>> to non-gooey-ness at a temperature and time that won't damage the playable
>> tape. If it were me with those tapes, I would invest a lot of time into
>> seeking backups, even off-air recordings if they are radio or TV
>> soundtracks. I think you stand a better chance of getting usable audio that
>> Martin, have you tried freon on those gobs? That's nasty stuff but it
>> worked really well on splices that had gone gooey on 1950's brown-oxide
>> tapes that were otherwise fine. The method was, use freon to dissolve the
>> splice-goo on the outside of the tape pack, slowly wind to the splice, then
>> very conservatively dab freon on whatever small globs of splice-goo were on
>> the tape. If the mylar back of the splice had dried out and thus broke the
>> splice, very conservative application of freon was used to dissolve all the
>> white dried out glue and sticky goo. Then a new splice was applied
>> (cleaning and re-splicing taking place in a splicing block). This worked on
>> 1/4", 1/2" tapes (both 1.5 mil thick) and 35mm mag-film. I'm wondering if
>> you can rig up something similar to attack those globs. I think your
>> problem might be that by the time you expose a glob, it's damaged the
>> playback surface (oxide)?
>> -- Tom Fine
>> ----- Original Message ----- From: "Jim Lindner" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Wednesday, February 08, 2012 6:19 PM
>> Subject: Re: [ARSCLIST] Tape Backcoating
>> Tom there are many instances where baking before cleaning is not advised,
>> and Martin nicely described just one of them. I would extend that and say
>> that there are many situations where baking is not advised at all, and if
>> so only after other processes have been tried beforehand and have failed
>> and all other avenues exhausted.
>> On this list, posters are used to discussion of primarily 1/4" audio
>> tape. There are, however, many different types of tape including ones that
>> have completely different binder system from 1/4" audio. Some stocks have
>> base films that are just fractions of the thickness of 1/4" audio and have
>> recording densities orders of magnitude higher then audio tape. Magnetic
>> Media is used in many different application areas and have totally
>> different formulations, thicknesses, and characteristics such as abrasivity
>> (for example) are totally different. Different tapes are designed for
>> differing head to tape contact and head tip penetration, and all of these
>> factors are critical in the development of appropriate product for the
>> recording format, and they are far from the same. Consider the differences
>> between MP and EM tape for example - there is almost nothing the same about
>> them other then them being called tape and them having recordings on them.
>> In almost all situations baking EM tape would be ill advised.
>> Some even have the word Video or Data or Instrumentation before the word
>> Tape. These tapes have different formulations and respond differently to
>> baking, and even more to the point, SSS is not just one thing and has
>> become a general description to a wide variety of maladies that vary a
>> great deal in terms of the amount of tenacity of the adhesive as well as
>> the location of it and the thickness and composition of it. While a tape
>> may be "sticky", the problem may not be SSS and so the appropriate
>> treatment of it may vary considerably.
>> Not all tapes have linear tracks - and tapes that have helical recordings
>> have some rather different issues then those with linear tracks.
>> Deformation in base film of linear recorded tracks - particularly if they
>> are wide half or full track audio recordings likely would not be an issue.
>> Deformations of basefilm for videotape that have helical recordings and
>> therefore have tracks across the tapes (and in particular azimuth
>> recordings on high density recording media), can lead to mistracking issues
>> and reduced rf output. This can lead to the loss of servo lock and
>> catastrophic failure to play back. This is because non-linear basefilm
>> deformation can cause the tracks to skew. Playing back skewed tracks in
>> some formats is extremely difficult - particularly when the skew is not
>> consistent from one section of the tape to the next - and the result can be
>> extremely serious. Some machines can compensate and other not, and this
>> varies for format type as well as particular machine models and even to the
>> specific machine being used for playback and its specific calibration at
>> that time. Interchange becomes a huge issue because the deformation of the
>> tracks creates a non-standard recording = sometimes - and it may only last
>> a millisecond or two.
>> Certain tapes have been exposed to damage during their life that would be
>> compounded by baking. Tapes that have, for example, particulate
>> contamination or have other types of contamination caused by floods or
>> exposure to caustic environments should not just be stuck in the oven
>> because they are sticky. I have personally dealt with tapes that have
>> become septically contaminated - and are sticky, but there clearly may be
>> other mechanisms in play that can cause the stickiness. Physically cleaning
>> tape prophylactically when performed correctly can and has often pre-empted
>> the need for baking in virtually thousands of tapes that I personally was
>> involved with over a decade. However, there is a certain amount of skill
>> and expertise required.
>> Taking 2 Asprin and calling the Dr. in the morning may be fine for the
>> common cold but not likely helpful for Appendicitis or Cancer.
>> Jim Lindner
>> Email: [log in to unmask]
>> Media Matters LLC.
>> 450 West 31st Street 4th Floor
>> New York, N.Y. 10001
>> eFax (646) 349-4475
>> Mobile: (917) 945-2662
>> 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.
>> On Feb 8, 2012, at 4:48 PM, Tom Fine wrote:
>> Who would "advocate" fast-winding or playing a sticky tape before it is
>>> baked? That is idiotic advice and should be ignored! The tape is _STUCK_
>>> (ie "sticky") and it will _SHED_ (ie layers of the tape will separate) if
>>> the tape pack is molested until it has been baked and cooled. I've never,
>>> never had a problem with tapes de-layering after they've been baked the
>>> proper time at the proper temperature. I have had tapes (Scotch 227, 3600'
>>> reels) that still deposit moderate amounts of white goo on the guides after
>>> proper baking and cooling, but they played back fine (there wasn't enough
>>> goo to jam up the tape travel).
>>> I can't understand why there is still any "debate" about this -- a
>>> sticky-shed tape needs to be baked before anything is done to the tape pack
>>> (playback, fast-winding, etc). The good news is, plastic reels can
>>> withstand recommended baking temps and times, and if they end up a little
>>> warped, just gently/slowly spool the baked tape onto a new reel and dump
>>> the warped one. If the tape is on a hub, I recommend you place a flange
>>> under the hub, bake it and then handle it very carefully because baking
>>> tends to result in a loose tape pack.
>>> -- Tom Fine
>>> ----- Original Message ----- From: "Nigel Champion" <
>>> [log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Wednesday, February 08, 2012 3:32 PM
>>> Subject: Re: [ARSCLIST] Tape Backcoating
>>> Perhaps the problem here is not that the tape was baked but that it was
>>> re-wound before baking! I cringe when I see this advocated.
>>> Pressure on inner windings in conjunction with sticky shed syndrome can
>>> create a core as solid as a hockey puck, especially if storage conditions
>>> have been sub-optimal. In such situations, pinning and delaminating is
>>> almost inevitable.
>>> Good luck
>>> Nigel Champion
>>> Archive Manager & Audio Conservator
>>> Archive Of Māori & Pacific Music
>>> The University of Auckland
>>> Private Bag 92109
>>> Auckland 1142
>>> Tel: 64-9-373-7599 ext 85008
>>> Fax: 64-9-373-7441
>>> Web: http://www.library.auckland.**ac.nz/ampm/<http://www.library.auckland.ac.nz/ampm/>
>>> -----Original Message-----
>>> From: Association for Recorded Sound Discussion List [mailto:
>>> [log in to unmask]**GOV <[log in to unmask]>] On Behalf Of
>>> Jim Lindner
>>> Sent: Wednesday, 8 February 2012 6:41 p.m.
>>> To: [log in to unmask]
>>> Subject: Re: [ARSCLIST] Tape Backcoating
>>> The backcoat binder system chemistry is in most cases similar if not
>>> identical to the oxide binder system, so it sounds like you really do have
>>> a mess. Removing one without damaging the other will be extremely
>>> difficult. It may be that using a pellon wipe to try to remove it not
>>> chemically, but through successive wipes at high speed MIGHT remove enough
>>> of it to allow playback, but I would have to see it to tell. It also might
>>> be that a low concentration of a solvent will remove the "low hanging
>>> fruit" first - so again a pellon wipe with a dilution of solvent and water
>>> might work - although you then have the rh issues to deal with, which might
>>> also cause problems. These are the "fast and cheap" approaches that might
>>> work - but then again you have tried fast and cheap already and have reaped
>>> the rewards.
>>> In the past I have used modified film rewinds (with a NAB hub to
>>> accommodate tape) and placed the supply reel on one side and the take up
>>> reel on the other side - oxide side up in your situation. In between you
>>> have your work surface, and you now hand "polish" the tape using a solvent.
>>> Unofficially I might suggest experimenting with the now banned 1:1:1
>>> trichloroethane using this modified film rewind approach. Although banned,
>>> it may still be available in small quantities from chemistry supply
>>> facilities, and yes it is expensive. Fortunately you do not need much. Read
>>> the MSDS very carefully, handle very carefully, adequate ventilation,
>>> follow all guidelines, hands end eye protection, ventilator - all of it.
>>> This will be a slow hand process. As you get experience you will be able
>>> to remove the goo and if you are careful in your application leave the
>>> stuff under it. Too much solvent and too much pressure and you will wipe
>>> all of it. You "polish" slowly foot by foot winding the completed and clean
>>> tape on the take up side. Based on your description you will need to also
>>> clean the back coat side because it sounds as if you have softened it
>>> enough so that it will reapply itself to the oxide if rewound on it
>>> directly based on the pack pressure.
>>> Yeah, well you really do have a mess and a science project. This is just
>>> one reason why I am not a big baking fan. There are not too many cases
>>> where I see media that is dumpster bound. Next time you might consider
>>> cleaning before baking.
>>> Jim Lindner
>>> Email: [log in to unmask]
>>> Media Matters LLC.
>>> 450 West 31st Street 4th Floor
>>> New York, N.Y. 10001
>>> eFax (646) 349-4475
>>> Mobile: (917) 945-2662
>>> 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.
>>> On Feb 7, 2012, at 5:18 PM, Martin Fisher wrote:
>>> Hey Guys,
>>>> What chemicals are good to strip backcoating off reel tapes.
>>>> NO! NO! NO! I don't want to send them out for stripping. Way too
>>>> expensive. I don't even want to strip the entire tape.
>>>> What I need is to clean the backcoat off the oxide layer. The tape was
>>>> given a "B" wind after developing sticky shed and, in places, some
>>>> backcoating "hairs" got stuck between adjacent layers and adhered to the
>>>> binder. This was exacerbated further by baking. The stuff just turned to
>>>> goo and spread out on the surface of the binder like butter on bread in the
>>>> Alcohol works but also dissolves the binder an many instances. No way
>>>> of knowing the tape stock since the boxes are generic, reels are haphazard
>>>> but the backcoating is of the thick, matte gooeyer variety.
>>>> Any help appreciated! :-)
> Richard L. Hess email: [log in to unmask]
> Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
> Quality tape transfers -- even from hard-to-play tapes.