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Re: [ARSCLIST] Fwd: Sticky AGFA PEM 469



I think the listing on the Ampex site of SSS tapes hits the high points.

There are multiple issues.

At this point there is one major failure mode for polyester (PET) base film magnetic tape:
BINDER / COATING SYSTEM DEGRADATION


This can manifest itself in many ways:
(a) Soft Binder Syndrome - I see this as generic where the binder softens
- on some tapes the glass transition temperature falls to below room temp
- one instance Tg was +8C measured
- cold playing may work on tapes that don't have other problems / solutions
- cold playing seems to work now on Sony PR-150 and 3M 175
(b) Sticky Shed Syndrome
- While the binder has gone soft there is far more shedding than the generic SBS
- Baking or Pellon wiping appears to cure this. I prefer baking
- Baking times are going up
- This appears to work with all of the tapes (except perhaps Q15) listed on
the Ampex site
(c) Loss of Lubricant
- While theorized, no tape has yet been identified chemically with LoL
- LoL in concept can be explained by not loss of lubricant but increase in friction
see (a) and (b) above
(d) Squeal that doesn't respond to (a) or (b) above that while probably not (c) can
nonetheless be played with additional lubrication be it isopropyl (Thanks, Kiwi) or
D5 (Thanks, Scott). Search MARIE in my blog
(e) In at least one instance with Shamrock 031 it did not respond to the indicated treatment
in (a) or (b) but higher speed playing on a different topology machine Search SHAMROCK
in my blog


Cheers,

Richard

At 07:15 AM 2008-04-03, Tom Fine wrote:
By the way, on another extreme are mass-market magazines like EQ and Mix and Electronic Musician who are vague about what tapes to bake or outright advocate baking all "old" tapes. This is completely wrong and a tape should only be baked or otherwise treated if it is known defective. Richard Hess will clarify, but I am pretty sure that the _vast_ majority of pre-1970 tapes hold up just fine over time and indeed will be damaged by baking or other treatments (apparently some early types suffer loss of lubricant, which is a different problem). And, Scotch 206/207 back-coated tape never suffered any problems according to both Del Eilers and Bill Lund formerly of 3M. Furthermore, early Ampex black-oxide tape, the non-back-coated types, seems OK, in fact I just recently transferred two reels of I think 424 or 434 type from 1969.

The big problem with these mass-market mags is they over-simplify (sometimes due to ignorant writers, sometimes due to an editorial mandate to keep things to idiot-simple talking points). In a nuanced and complex problem set like what confronts old tapes, this is dangerous and ignorant.

My point is, the most important thing we can do with old tapes is to suss out what type is actually in the box, first and before anything action is taken. My experience is that many tapes arrive in white boxes or generic boxes and often if there is a tape type label on the box, what's in it is not that. And then we have mixed-type reels which are their own special hell. Once we suss out exactly what's on the reel, we can then be on the lookout for any problems associated with that kind of tape.

-- Tom Fine

----- Original Message ----- From: "Tom Fine" <tflists@xxxxxxxxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Thursday, April 03, 2008 6:26 AM
Subject: Re: [ARSCLIST] Fwd: Sticky AGFA PEM 469


Hi Parker:

Regarding this page:
http://www.recordist.com/ampex/docs/misc/sticky-shed.html

I think Ampex tape was sticky past the mid-80's, despite some Ampex claims. As I understand it, 406/407/456 was likely to go sticky into the early 90's. Some say ALL of these tapes will eventually go sticky. I have 456 and 406 and 457 from the late 90s and early this decade and so far no problems with sticky. But, it's early ...

-- Tom Fine

----- Original Message ----- From: "Parker Dinkins" <parker@xxxxxxxxxxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxxxxxx>
Sent: Wednesday, April 02, 2008 10:07 PM
Subject: Re: [ARSCLIST] Fwd: Sticky AGFA PEM 469



on 4/2/08 8:49 PM US/Central, Steven Smolian at smolians@xxxxxxxxx wrote:

There is (was?) a 3M site that lists all the tape product numbers and
indicates their liklihood of getting the dreaded shed.  Del Eilers put the
list together before he moved elsewhere withing the company.

Maybe this is list you are referring to -


http://www.recordist.com/ampex/docs/misc/sticky-shed.html

While Del Eilers' list of 3M tape products can be found here -

http://www.recordist.com/ampex/docs/aorprod2.html

--
Parker Dinkins
MasterDigital Corporation
Audio Restoration + CD Mastering
http://masterdigital.com


Richard L. Hess email: richard@xxxxxxxxxxxxxxx
Aurora, Ontario, Canada (905) 713 6733 1-877-TAPE-FIX
Detailed contact information: http://www.richardhess.com/tape/contact.htm
Quality tape transfers -- even from hard-to-play tapes.



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