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Re: [ARSCLIST] revisiting tape bakers
To be blunt, I know many people and organsiations who use baking as the
preferred method.
I would like to know -
1) Who has used Rezerex?
2) What does it involve?
3) How long does it take for one tape? (eg. 7inch reel @ 7/12ips)
4) What does it cost? (eg. 7inch reel @ 7/12ips)
Cheers
Marie
On Sat, Nov 8, 2008 at 7:00 AM, Charles A. Richardson <
charlesarichardson@xxxxxxxxxxx> wrote:
> Hi Richard:
>
> There has been a continuing discussion of baking as a remedy for sticky
> shed contamination on magnetic tapes. List members point to the Ampex
> Baking Patent as authority for baking sticky shed tapes to enable playback.
> The discussion seems to assume the safety or ignore the damage that baking
> does to tapes. Baking is dangerous and much of the information about baking
> tapes is misleading. The following is not just my opinion or assertion but
> has been substantiated by the scientific analysis of a nationally
> recognized, independent forensic chemical laboratory.
>
> 1) The baking process set out in the Ampex Patent melts the sticky shed
> debris with heat energy. This stops tape
> frictional squealing while the sticky shed debris remains in a liquefied
> state, but the squealing returns after the debris cools off and solidifies
> once more. It does not cure the underlying chemical causes of the tape
> problems which return endlessly.
>
> 2) Magnetic tapes are made with complex chains of polymers. The polymer
> links are extremely heat sensitive. Baking destroys the flexibility of the
> tape and the binder adhesion because it damages the links in the chemical
> chains. Applying heat permanently breaks down the chain links, causes
> unwanted new cross linking of chemical bond links, and creates new, unwanted
> chemical compounds. The tape becomes increasingly brittle and the coatings
> start to flake off the base film. Repetitive baking increases the damage to
> the chemical, magnetic and physical components, and eventually destroys the
> tape.
>
> 3) Sticky shed debris, liquefied by baking, collects at the tape head gap.
> This debris accumulation pushes the tape oxide surface further and further
> away from the tape head's surface at the critically important head gap.
> This collection of debris causes a physical and major magnetic separation
> loss, which, as you know, severely reduces the ability of the tape head gap
> to magnetically scan the short wave lengths of the oxide's recorded content
> at high frequencies. This results in inferior mechanical, magnetic and
> sonic playback performance and thereby a deficient transfer of tape content.
> The playback head's high frequencies are greatly reduced, the noise
> reduction system playback performance mis-tracks, and worsens these high
> frequency losses. Thus the tape sound quality is now made dull and lifeless
> because sticky shed debris on the head gap magnetically attenuates proper
> and complete scanning of the important high frequencies that are now greatly
> reduced or even missing altogether.
>
> 4) Baking causes increased print-through.
>
> 5) Baking causes weakened magnetic fields and thus lower flux and output
> signal levels.
>
> 6) Baking does not provide any "restoration" or "rejuvenation" of binder
> chemicals. To the contrary, it causes progressive
> and permanent damage to and destruction of the tape. A fundamental thermal
> law of chemistry is that heat energy destroys
> substances.
>
> 7) Baking is not a safely repeatable solution. Each time a tape is baked,
> it requires higher temperatures and/or longer bake times. Each round of
> baking produces worse chemical, physical, magnetic, mechanical, and sonic
> results.
>
> 8) The high heat used in baking drives off by evaporation the light weight
> polymers and causes the magnetic particle material attached to them to fall
> off.
>
> 9) Baking the tape damages the tape's magnetic content and seriously
> degrades the playback performance. People have ruined tapes by baking them,
> but this is generally not admitted, possibly because of fear of liability
> and potential loss of income. They may be unaware of any other method to
> stop tape squealing safely and permanently.
>
> 10) Some proponents of baking try to rationalize this dangerous baking
> method by inventing a new set of terminology and
> circumstances, such as "soft binder syndrome", to justify using the baking
> technique to obtain a mediocre playback. I am unaware of any scientific
> evidence or support by an independent laboratory for "soft binder syndrome"
> as either being separate and distinct from or a sub-set of sticky shed
> syndrome.
>
> 11) The accurate standardized chemical terminology is that tape binders
> are inherently hygroscopic, and thus are susceptible to hydrolysis. The
> only safe and highly effective method to restore and preserve tapes
> suffering from hydrolysis of the binders, or sticky shed syndrome, is to
> first, put the affected tapes in a stable environment of low heat and
> humidity for as long as it takes to reverse the hydrolysis reaction, and
> then second, safely clean all the tape's debris from both the oxide surface
> without damaging the surface, and also completely remove its chemical
> material causal source, namely the deteriorated carbon black back coating.
>
> 12) Much reliance has been placed, or should I say misplaced, on the Ampex
> Baking Patent. The Ampex Baking Patent is intended solely to expedite the
> transfer of recorded information. The title, "Restored magnetic recording
> media and method of producing same", is inaccurate because the baking method
> does not take steps to preserve the media, but only to restore temporarily
> a "playable condition" in the media. It is merely a band aide fix, not a
> cure.
>
> 13) The 1993 Ampex Baking Patent suggests that heating tapes to 120-130
> degrees Fahrenheit "does not further deteriorate the tapes" and implies that
> baking a tape for prolonged periods of time is safe. The patent does not
> cite scientific or chemical evidence to back the "no further deterioration
> claim". Moreover, the claim runs directly contrary to pre-existing chemical
> thermal laws and 1980 scientific findings that heat damages tape's magnetic
> content by increasing print through levels, published in a scholarly article
> written by Ampex's own staff scientist, H. Neal Bertram. "The Print Through
> Phenomenon" (JAES Volume 28, Issue 10, pp.690-705; October 1980).
>
> 14) The elevated temperatures stated in the Ampex Baking Patent, 120-130
> degrees, also violates Ampex's own tape manufacture's warranty limiting heat
> to not exceed 90 degrees. This chemically abusive high baking heat
> radically shortens tape lifespan to a small fraction of the time tapes can
> last if they are instead stored and handled as chemical science requires.
> Tapes have the ability to be reliably archival for a very long time.
> However, if abused by improper storage, handling, and wrong headed
> restoration, then tapes are damaged, degraded, and destroyed far ahead of
> their time.
>
> 15) As you know, a patent does not confer a certification or implication
> that an invention is scientifically proven to be effective or safe. A
> patent is a grant from the U. S. government (or other authority in other
> countries) of a right to exclude others from making, using, or selling one's
> invention and also includes the right to license others to make, use or sell
> it.
> A patent application is only narrowly and formally reviewed to determine
> whether the invention is entitled to be granted a patent under U. S. Patent
> law. The most important requirement under U. S. Patent law is that the
> invention be a new or useful process, machine, manufacture, or composition
> of matter, or any new and useful improvement thereof. Clearly, a patent,
> baking or otherwise, is no scientific authority and no certification of
> safety.
>
> 16) Richardson Magnetic Tape Restoration is concerned, not just with
> minimal baking type partial recovery of the magnetic content information
> contained within a sticky tape, but with the long term preservation of
> magnetic tapes as the primary or original source of the all the magnetic
> content information on the tapes and to create optimal playback conditions
> for high quality reproduction needs. To achieve this goal, RMTR hired a
> nationally recognized independent forensic chemical laboratory to test
> chemically and to examine under a high power electron microscope, the sticky
> shed tapes, before and after application of baking heat treatments. The lab
> results showed significant deterioration of the tape after it was heated as
> per the Ampex baking patent. Application of heat treatments, the chemists
> concluded, accelerates even more damage from hydrolysis, and increases the
> cross linking of the polymers used in making the PET Mylar base film and
> binder components of the tapes. This baking practice soon "leads to
> unwanted tape destruction." The chemists also concluded that the new RMTR
> process was both safe and effective for tape restoration, preservation, and
> playback mastering needs.
>
> I have a written paper that elaborates on these concepts. The paper is
> available on request.
>
> If you or any other list members have independent chemical laboratory
> research that refutes these points or supports baking as both safe and
> effective for the restoration and preservation of magnetic tapes, I would
> appreciate seeing it.
>
> Charles A. Richardson, RMTR LLC
>
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> On Sep 27, 2008, at 8:42 PM, Richard L. Hess wrote:
>
> At 08:05 PM 2008-09-27, Tom Fine wrote:
>>
>> I forgot if Richard has a complete list of must-bake types on his website.
>>> If so, I'm sure he'll provide a link.
>>>
>>
>> I do and your points that I snipped are important for those who haven't
>> heard them before.
>>
>>
>> http://richardhess.com/notes/2007/03/21/soft-binder-syndrome-and-sticky-shed-syndrome/
>>
>>
>> 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.
>>
>