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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc.

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Old 20th Sep 2017, 2:17 pm   #1
toshiba tony
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Default Tape shedding?

You people have been so kind over the the years. I hadn't come across the tape shedding issue on reel to reel. Apparantly it also occurs on cassettes. I've been advised to remove any valuable data. I have two good cassette decks and used to be conversant with mp3 but due to a dementia issue I get stuck.What I want to know is this? The tapes that are exhibiting the shedding issue, can this harm the tape heads on my reel to reel? Top end response is fine, but I want my deck to see me out. Ta all.
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Old 20th Sep 2017, 2:35 pm   #2
paulsherwin
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Default Re: Tape shedding?

Classic sticky shed happens when the tape binder absorbs moisture. It mostly affects 1970s American professional formulations that used a particular DuPont binder. Unfortunately these were very widely used in the recording industry.

Cassette tapes don't use these formulations so sticky shed is very rare. You may be confusing it with oxide shedding, where oxide particles come off the tape and are deposited on the tape heads and guides. This is usually at its worst the first time the cassette is played after a long period in storage. The oxide doesn't damage the deck and can be cleaned off in the normal manner.

If sticky shed is present, it will leave sticky deposits which are difficult to clean off, but there is no real permanent damage to the deck (as opposed to the tape itself).
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Old 20th Sep 2017, 4:51 pm   #3
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Default Re: Tape shedding?

There is not excessive tape oxide deposit on the heads. Just a horrible squeak as the tape passes through the guides and heads. As you may guess, this drops a shade if I reduce the back tension. But am I causing more head wear? It doesn't sound pleasant, I don't mean the warbled effect through the speakers. I mean the tortious sound from the tape. I cringe!

I need to have a good day from dementia and focus on transferring the data on the tapes. Idleness I know!
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Old 20th Sep 2017, 4:57 pm   #4
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Default Re: Tape shedding?

That probably explains why the only problem I have had with tape shedding is with commercial pre-recorded cassettes. The worst affected is my copy of "The shadows greatest hits", which sheds so badly that the heads need to be cleaned with Meths and a cotton bud after only half a side has been played. I solved the problem by finding a copy on Vinyl in a charity shop! No problems whatsoever with my own off-radio recordings from the 1970's on BASF, Philips, TDK or Maxell.
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Old 20th Sep 2017, 4:57 pm   #5
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Default Re: Tape shedding?

Sorry, won't post again. It's only Gustav Holst and Eric Sate. I can get them on iTunes
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Old 24th Sep 2017, 10:11 pm   #6
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Default Re: Tape shedding?

The squeak is possibly a precursor to shedding. Or it could also be caused by a loss of lubricant on the tape surface. Loss of lubricant is rarer than sticky shed but it affects a wider range of tapes. The best solution is to play the tape on a machine with roller guides everywhere but some people have other solutions. Take a look at

http://richardhess.com/notes/2006/03...arie-oconnell/

for more information.
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Old 25th Sep 2017, 6:52 am   #7
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Default Re: Tape shedding?

I once saw a case of a tape head damaged from tape matter which stuck to the head face and remained there for a long period of time. Cleaning off the tape matter revealed corrosion of the head face. I guess the moisture in the hygroscopic material slowly ate away at the head face. The head was from a Revox B77 and was expensive to replace. I guess it could happen to many brands of head. Ever since, I've been careful to clean tape heads AFTER having played questionable tapes and before storage of the machine.
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Old 25th Sep 2017, 9:32 am   #8
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Default Re: Tape shedding?

Tony, I'll repeat this just in case you have forgotten.
I had exactly the same problem with some of my old tapes. The tape would bind and squeak and sometimes jam completely. The squealing could be heard faintly on the playback audio too. I managed to salvage some of the tapes by fast forwarding the tape against a cotton wool pad moistened with isopropyl. I also thoroughly cleaned everything in the tape path. This made the tapes playable for long enough to transfer then to MP3 format.
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Old 26th Sep 2017, 3:58 am   #9
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Default Re: Tape shedding?

Quote:
Originally Posted by paulsherwin View Post
It mostly affects 1970s American professional formulations that used a particular DuPont binder. Unfortunately these were very widely used in the recording industry.
Just to clarify - they may be 70s formulations, but use continued into the 1990s. I have Ampex 456 from 1993 that has sticky shed.

Quote:
Originally Posted by paulsherwin View Post
Cassette tapes don't use these formulations so sticky shed is very rare. You may be confusing it with oxide shedding, where oxide particles come off the tape and are deposited on the tape heads and guides.
Interestingly, I have two early 80s BASF type I cassettes (one "Ferro Super" green one, the other a yellow one) that don't exhibit squeeking, but do leave a lot of oxide on the heads after a few seconds. The oxide is not as hard to clean as true sticky shed from the likes of 456, but it is enough to know that attempting to play the tapes will destroy the content. I haven't gotten around to trying to bake them yet.
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Old 26th Sep 2017, 10:42 am   #10
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Default Re: Tape shedding?

It's unusual for cassettes to shed so much oxide that they become unplayable, but they can certainly be difficult to play for the first time after storage. The heads will require cleaning every few minutes in bad cases.

Sticky shed is really a specific problem affecting Ampex and other American pro tapes, and you're right, the formulations were still being made into the 90s. These tapes were the pro industry standard. The impact has been much less after the early 80s because of the general move to digital recording and mastering in pro audio. Most of the original analogue multitrack tapes, studio masters and cutting masters from the 70s are now unplayable. The industry did recognise this problem in the 90s and most of the important stuff was salvaged and digitised then, but some material is now only retrievable from 1980s CD reissues or even commercial vinyl releases.

Old tapes can be difficult or impossible to play for many reasons, and all these tend to be lumped together as 'sticky shed', though really there can be multiple factors involved.
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Old 26th Sep 2017, 1:48 pm   #11
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Default Re: Tape shedding?

Quote:
Originally Posted by paulsherwin View Post
Most of the original analogue multitrack tapes, studio masters and cutting masters from the 70s are now unplayable.
I assume you mean unplayable without baking - I regularly transfer master tapes from the 70's up to the 90's here and I don't think I've encountered any master that has been totally unplayable.

I did encounter some cassettes from the 80's that became hard to play after only a few months thanks to oxide shedding - I can't remember the make but they may have been Racal or Pyral.
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Old 26th Sep 2017, 2:24 pm   #12
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Default Re: Tape shedding?

I understand a lot of them are now difficult to play even with baking, especially if they've been baked previously. I'm not a professional though, and am only repeating what I've read.

I used some blank Pyral cassettes in the late 70s. They were awful for oxide shedding, even when new.
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Old 26th Sep 2017, 11:16 pm   #13
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Default Re: Tape shedding?

Ted Kendall has mentioned in another thread that he has had to increase his baking temperature over the last few years and my experience seems to be similar - my first successful tape baking session went up to 43 degrees C but nowadays I'm going up to 50 degrees or higher.
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Old 27th Sep 2017, 7:30 am   #14
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Default Re: Tape shedding?

I don't think temperatures have changed that much, and in any case 55 or so is the practical limit - the major change is in duration. What took hours now sometimes takes four or five days, and of course it's best to err on the side of caution. Cassettes are a slighlty different case - the tape is thinner, and you don't want to warp the case and add to your troubles - I wouldn't go beyond 50 to start with, and try after 24 hours or so.
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Old 27th Sep 2017, 11:45 am   #15
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Default Re: Tape shedding?

I wonder if the longer baking times (a result of the binder degradation becoming worse as the years go by?) will eventually render the method impractical?
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