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Hi Tom Just a clarification. My problem was with the 206 and 207 but was that it delaminated. 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 3:33 AM, Tom Fine <[log in to unmask]> wrote: > 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". >>> >> >> >>