Hi Will;  Sorry about your problems.  In order to prevent this, one  
needs to know the basics of chemistry/biology and  take the right  
steps to stop it.   Generally, any organic material in the presence of  
moisture is a candidate for mold and fungus problems.  Mold and fungus  
are primitive organic biological life forms which feed upon organic  
materials in a weakened or near terminal state.  Mold and fungus acts  
as a scavenger or a  'funeral undertaker' in completing the organic  
life cycle of living substances.   In magnetic tape, all its  
chemicals, with the exception of the inorganic magnetic particles and  
perhaps some lubricants, can be attacked by mold and fungus.  Thus the  
base film, the binder chemicals, and the carbon black back coating  
substances are open to this attack.   Ordinary air usually has some  
free mold and fungus spores in it. When these spores can land, find a  
suitable home and growth situation, they will reproduce explosively,  
doing the damage you mention.  Being living predatory parasitic  
organisms, they must have food for their life and reproduction cycle.  
Thus they then eat away at tapes and other tasty organic materials.   
Some mold and fungus has a powerful appetite and it "Pigs Out" rapidly  
on its prey while other forms "take it slow."   There are various  
remedies, some safe and some not.  One does need to take precautions  
to stop the outbreak or spread of mold or fungus and also to prevent  
personal injury and health problems.   There are parties who know how  
to do this safely.

As to attacking tape heads, etc, no, the mold and fungus does not  
attack them directly because these items are inorganic materials.   
However, mold and fungus have a physical structure similar to that of  
a sponge and thus can carry and/or retain other chemicals that will  
attack the heads.   The additional moisture in the fungus can directly  
oxidize the metal parts,.  If the moisture combines with other tape  
chemicals,  then alcohol, carboxyl acid or hydrochloric acid can be  
generated which will attack the heads.  Cross contamination from the  
tape, to the tape machine parts, and then to more tapes is certainly a  
possibility. It does happen in some cases.  However, a very thorough  
effective cleaning can usually prevent this.

You are also correct that in general, the tape problems are getting  
worse. The reasons are multiple and interactive.  There are some  
problems in the manufacture of tape, with the carbon black back  
coating being one of the worst chemical mistakes of all time.  It is a  
moisture sponge and a seed bed for the growth of mold and fungus.  In  
my laboratory work and published chemical paper, there is direct  
visual microscopic evidence why this is the case.  Shown are high 800X  
magnification pictures of the mold and fungus attacking the carbon  
black.  Tapes which do not have the carbon coating are generally much  
more resistant to the deterioration problems. When the carbon black is  
completely removed from both tape surfaces, the mold and fungus it  
contains is removed and disposed of.  The restored tape recovers  
superbly to a nearly new condition.  So far there has not been a  
recurrence of mold and fungus attacks with properly restored tapes.   
Do take note of the real fact that tapes have extraordinary positive  
chemical capabilities. If handled right they will be cured of their  
problems, come back to normal use, and  be highly archival with superb  
sonic performance.  The tapes can last for the ages, provided they are  
not subjected to ruinous abused by ill considered destructive  
remedies.  Human mistreatment of one kind or another is
the major source for causing and failing to permanently fix the tape  
problems.  Treat a tape respectfully with clear headed, complete,  
correct, and comprehensive chemical understanding and it will return  
the favor many times over.

It is remarkable that with 30 years of major tape problems,  endless  
complaints from customers, dispositive laboratory evidence,  that  
tapes continue to be made with the awful carbon black coating. This   
repeated error just guarantees more future tape problems of the very  
same kind will come to pass year after year.  Many parties opine that   
a tape is inherently inferior if it does not have carbon black coating  
on it.  Analytic Chemists know better.   However, tape makers are  
pressured by the market to add the carbon coating to the tapes, in  
complete disregard of the chemical analysis not to do so.

Other problems arise from handling and storage issues.   Many quick  
fix remediation methods make matters much worse, not better, because  
of the many inherent damaging magnetic and chemical consequences.   
Even so,  typical tape problems can  be corrected if there is the  
willingness and ability to do strict chemical science and use new  
restoration methods with exacting precision.  However, If the current  
entrenched erroneous beliefs and practices continue unabated, the  
future is grim and dim not only for tape but many other media, etc,   
The increasing negative trend towards tape disaster is not forced upon  
us by inexorable fate. It is largely brought on by human failure to do  
and then follow the high level sophisticated chemical science the  
matter requires for solution.

Best Wishes,  Charlie Richardson

On Jul 21, 2008, at 9:31 AM, Prentice, Will wrote:

> The following quote is taken from the website of an audio transfer
> business in the southwest of Scotland ( 
> )
> "[Mould on tapes is] caused by storing tapes in damp or humid places
> during warm moist Summers and its destroying tapes as never before.  
> Its
> as infectious to other tapes as measles is to children and if it gets
> onto the recording heads of tape players it destroys them too, as well
> as infecting every other tape played on that machine. So its not
> surprising that there isn't a professional audio restorer in the World
> that will handle mouldy tapes. From a rare phenomena seven years ago  
> its
> now affecting almost ten per cent of all the old audio and video tapes
> seen by specialist audio restorers."
> Does this reflect anyone else's experience?
> Will
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