I'd be interested to read about it as well.

Cheers
Shai Drori
Expert digitization services for Audio Video
Hi Res scanning for film 8mm-35mm
www.audiovideofilm.com
[log in to unmask]

On Thu, Jan 21, 2016 at 10:51 PM, John Schroth <[log in to unmask]>
wrote:

> Maybe Peter does not know about Richardson's method Tom - it might be
> worth explaining briefly as it is a unique concept.
>
> Regards,
>
> John Schroth
> MTS
>
> On 1/21/2016 3:36 PM, lists wrote:
>
>> Tom:
>>
>> Didn't mention Richardson's method because I haven't used it and have no
>> test data to supply. At this point, we have other methods that work. The
>> only tapes we can't consistently restore are those where the recording
>> layer
>> has fallen off the base coat. We do have a method that can salvage some
>> of
>> these tape if treated before the oxide is actually missing and is just
>> loose
>> Unfortunately, this only works about 50% of the time and if the oxide is
>> already gone, not much anyone can do about it. The method is , once
>> again,
>> an application of basic polymer science, just a different approach- no
>> baking involved.
>>
>>
>> Peter Brothers
>> SPECS BROS., LLC
>> 973-777-5055
>> [log in to unmask]
>> Audio and video restoration and re-mastering since 1983
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: Association for Recorded Sound Discussion List
>> [mailto:[log in to unmask]] On Behalf Of Tom Fine
>> Sent: Wednesday, January 20, 2016 8:33 PM
>> To: [log in to unmask]
>> Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson
>> treated
>> tape
>>
>> Hi Peter:
>>
>> Once again, very useful info. Thanks for taking the time.
>>
>> Interesting to know so many different formats of tape get hydrolysis. As I
>> said, in the cases I cited, baking made the tapes playable, so that's what
>> it must be. Including the TDK DATs.
>>
>> You're being very specific about not mentioning Richardson's method. Have
>> you tested it in your laboratory? I will definitely keep this forum
>> informed
>> about how my treated tape does over time, but my testing is unscientific.
>> I
>> just play the thing once a year and see if it leaves residue, and compare
>> the output to previous captures, which is really not scientific either
>> because tape machines get used all year and there's no guarantee that the
>> heads and electronics are working exactly the same each time the tape is
>> played. I will say that no sticky tape I've had except this one stayed
>> un-sticky 1+ year after treatment. All previous treatment was traditional
>> baking.
>>
>> -- Tom Fine
>>
>> ----- Original Message -----
>> From: "lists" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Wednesday, January 20, 2016 4:50 PM
>> Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson
>> treated
>> tape
>>
>>
>> Hallo again:
>>>
>>> LOL does not respond well to baking. If the lubricant is gone, it is
>>>
>> gone-
>>
>>> baking will have no effect. If the lubricant has crystalized, the
>>>
>> crystals
>>
>>> will melt near room temperature- again, no reason to bake. Note; both
>>> assertions backed up by laboratory testing. If you are baking standard
>>> audio cassettes successfully, they probably have some degree of
>>>
>> hydrolysis.
>>
>>> It appears somewhat different as the binder is thinner (less binder to
>>> decay), the interface between the tape and heads is smaller (less surface
>>> for frictional problems to be noticed) and many of the cassettes are not
>>> backcoated (less tendency to hydrolyze so less oligomer residue). We
>>> have
>>> encountered many audio tapes with hydrolysis. The effects on the tape
>>>
>> just
>>
>>> appear different than on larger tapes. It is one of the reasons I'm not
>>> particularly fond of the popular term "sticky shed" when the actual
>>>
>> problem
>>
>>> is "binder hydrolysis". Hydrolysis can easily cause tapes to have a
>>>
>> higher
>>
>>> frictional coefficient without significant, visible shedding. Ok,
>>>
>> "sticky
>>
>>> shed" sounds way cooler but it can obscure the actual chemical reaction
>>>
>> that
>>
>>> is happening and result in incorrect assumptions. If your audio tapes
>>>
>> jam,
>>
>>> stick or run slow in your machinery and respond to "baking", the problem
>>>
>> is
>>
>>> much more likely to be hydrolysis than LOL.
>>>
>>> As for video tape, nearly all 1/2" open reel videotapes now exhibit
>>> hydrolysis to some degree. The majority of 3/4" video made between 1975
>>>
>> and
>>
>>> 1985 also exhibit hydrolysis (ok, Il use "sticky shed"). Many Ampex 3/4
>>> from this era are so bad that, when put in the playback machine, they
>>>
>> almost
>>
>>> immediately seize up and will not move. 1" and 2" videotape also
>>>
>> frequently
>>
>>> have sticky shed.
>>>
>>> DATs, in my experience, not so much. Yes DATs have problems but we have
>>> been able to restore DATS to playable condition by cleaning and polishing
>>> the tape surface- no baking. The DATs are shedding and won't play back
>>> properly but we have found they don't need baking- they seem to just be
>>> falling apart. There is also a problem with the load mechanism in many
>>>
>> DAT
>>
>>> machines that goes slightly out of alignment very easily and abrades the
>>> tape during playback transport, causing additional shedding. None of the
>>> DAT info here is backed up by laboratory testing; just my experience. If
>>> others have had success with baking, there may be a hydrolysis issue. We
>>> may have just overcome the minor hydrolysis on the surface with the
>>>
>> cleaning
>>
>>> and polishing.
>>>
>>> Finally, a few thoughts on signal loss with baking. It is possible that
>>> baking might cause some irregularity on the tape surface. I haven't seen
>>> laboratory evidence of this, however, and we always clean tapes after
>>>
>> baking
>>
>>> them so any irregularities would likely be smoothed out. I have seen
>>> tape
>>> under electron microscope[e that clearly shows tape surfaces are rougher
>>> right after manufacturing than they are after a few record/playback
>>>
>> passes.
>>
>>> I have always been amazed that there is no conclusive laboratory evidence
>>> for the audio loss. Everything is hearsay but it really should not be
>>>
>> that
>>
>>> hard to set up an easily repeatable and fairly inexpensive test for this.
>>>
>>> Another possibility is "thermal idiots". Nice technical term but, hey,
>>>
>> the
>>
>>> technical name for the insulating powder added to high density magnetic
>>> recording mediums to counter superparamagnetic effects is "Pixie Dust".
>>>
>> In
>>
>>> any case, the magnetic particles on many older analog tape had a wide
>>>
>> range
>>
>>> of coercivity and retentivity. This is one of the reasons for
>>>
>> print-through
>>
>>> where the lower coercivity pigments get affected by the magnetic field
>>>
>> from
>>
>>> pigments in adjacent wraps. Heat is also well known to weaken magnetic
>>> characteristics of many materials (including those the magnetic pigments
>>>
>> are
>>
>>> made of). If low retentivity pigments are subject to heat, it is quite
>>> possible they will lose or have the magnetic moment on the pigment
>>>
>> effected.
>>
>>> This is one of the ways print through is treated- the tape is
>>>
>> wound/rewound
>>
>>> and the low coercivity/ low retentivity pigments that picked up the print
>>> through are scrambled by the combination of the mechanical shock from
>>> transport as well as the heat generated by the transport friction; and
>>>
>> the
>>
>>> print through is reduced. Just an idea as far as possible loss of signal
>>> during "baking" is concerned, but it is consistent with magnetic theory.
>>> This doesn't mean I am asserting that this is what is happening, as we
>>> haven't seen a problem with signal loss, but it does match the science-
>>>
>> now
>>
>>> we just need someone to do some controlled testing.
>>>
>>>
>>>
>>> Peter Brothers
>>> SPECS BROS., LLC
>>> 973-777-5055
>>> [log in to unmask]
>>> Audio and video restoration and re-mastering since 1983
>>>
>>>
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: Association for Recorded Sound Discussion List
>>> [mailto:[log in to unmask]] On Behalf Of Tom Fine
>>> Sent: Wednesday, January 20, 2016 3:01 PM
>>> To: [log in to unmask]
>>> Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson
>>>
>> treated
>>
>>> tape
>>>
>>> Hi Lou:
>>>
>>> I agree, having transferred 1000+ cassettes over the years, that what we
>>> call Sticky Shed has never cropped up. However, there have been cases of
>>> Loss of Lubricant (LOL) or something similar, which has rendered the
>>> cassette unplayable without baking. Baking has worked for me every time.
>>> I've encountered this mostly with black-oxide off-brand cassettes, circa
>>> 1980s and early 1990s, some of which have been mass-duped (ie
>>>
>> professionally
>>
>>> duped and packaged for mass-market release).
>>>
>>> The other thing I have encountered, mainly with Scotch brand CRO2 tapes
>>> circa 1980s and late 1970s, is terrible warpage that leads to the tape
>>>
>> pack
>>
>>> sometimes being too big to fit in the shell. My solution to this has been
>>>
>> to
>>
>>> very carefully hand-wind enough of the tape-pack over to one side so both
>>> sides move comfortably in the shell, then splice one side into a new
>>> cassette housing, transfer both tapes and edit together in the proper
>>> sequence in the DAW.
>>>
>>> By far the biggest problem I have encountered with cassettes is the
>>>
>> pressure
>>
>>> pad having come unglued. I generally transplant those tapes into a new
>>> shell. You can still find screw-together C-0 cassette shells out there
>>> for
>>> sale, but I usually use one of hundreds of old Maxell and TDK tapes I've
>>> accumulated into a big box, just for that purpose.
>>>
>>> There has been talk out in the video world, some of it on the Ampex List,
>>> about certain videotape brands that develop Sticky-Shed and/or LOL. There
>>> are definitely some DAT types that develop something that makes them
>>> gooey
>>> and non-playable. I've enountered this with TDK brand DAT tapes, and
>>>
>> baking
>>
>>> has made them playable.
>>>
>>> When Telarc Records was reissuing their Soundstream recordings, which
>>> were
>>> on 1/2" instrumentation tapes, standard practice was to bake the tapes in
>>>
>> a
>>
>>> convection oven. I don't know exactly what brand and type tapes they
>>> used.
>>>
>> I
>>
>>> don't know enough about reel to reel digital tape systems to know if DASH
>>> tapes need baking.
>>>
>>> What is still mysterious to me is why some tapes of a type not known for
>>> sticky-shed will go sticky.
>>> For instance, Shai has reported all kinds of problems with Scotch 206 in
>>> Israel. I've never had one sticky 206 tape here in the US northeast. And
>>>
>> the
>>
>>> same with vinegar syndrome. Some people report never having problems with
>>> Scotch 111, yet my experience is about 50-50 whether a tape will go
>>>
>> vinegar
>>
>>> and start edge-curling or not. Audiotape acetate-backed seems less
>>> likely,
>>> but I've sure encountered my share of those tapes going vinegar. And yet
>>> almost all types of 35mm acetate-backed audiofilm will go vinegar.
>>>
>>> -- Tom Fine
>>>
>>>
>>> ----- Original Message -----
>>> From: "Lou Judson" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Wednesday, January 20, 2016 2:36 PM
>>> Subject: Re: [ARSCLIST] One more sticky-shed data point - Richardson
>>>
>> treated
>>
>>> tape
>>>
>>>
>>> Here's a slightly offtopic question. I shared the post of Peters' with an
>>> associate, with whom I am
>>> involved in a restoration project involving cassttes tapes from the 70s
>>> through the 1990s. We are
>>> wondering why audio cassettes are so rarely having sticky-shed problems.
>>> I
>>> know that has been
>>> discussed occasionally here, but why are cassetes relatively immune?
>>>
>>> <L>
>>> Lou Judson
>>> Intuitive Audio
>>> 415-883-2689
>>>
>>> On Jan 20, 2016, at 10:33 AM, lists <[log in to unmask]> wrote:
>>>
>>> Hello all:
>>>>
>>>> Coming very late to this thread. I don't intend to talk here about Mr.
>>>> Richardson's process but, in answer to Tom's post, I'll try to address
>>>>
>>> some
>>>
>>>> of the issues with "sticky shed".
>>>>
>>>
>>>
>> -----
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>>
>>