Hi Trey:
The mold issue is an important one. Do take proper and safe care in
handling the tapes. Your posting is missing some important
information, which, if known, would help in a better response. If
you list the make and model of tape, its age, how long in its present
storage condition, etc., that information helps. Mold and fungus is
a major biological/chemical deterioration mechanism which typically
breaks down dead, or nearly dead, organic matter into its final phases
of decomposition for eventual reprocessing in the larger biological
life cycle. Almost any and all organic carbon based material in the
presence of moisture can develop mold or fungus issues. Tapes and
most all recording media is made using organic chemicals and plastics
of various kinds. Thus the extreme importance for any organic media
for proper storage conditions with relatively low humidity and normal
moderate storage temperatures to either prevent mold and fungus from
occurring in the first place, or to slow it down as much as possible.
High humidity and/or high temperature of any type or kind makes
everything worse by accelerating unwanted chemical activity. The
biggest offender for tape mold and fungus issues are those tapes made
with a carbon black back coating. The chemically weak carbon black
back coating in poor storage environments quickly and badly
deteriorates in a progressive fashion, usually within a few years of
the tape's manufacture. It also chemically attacks the rest of the
tape. However, the other tape chemicals of the base film and oxide
coating do last a lot longer and they can be fairly, but not
perfectly, resistant to these moisture problems for a long time
provided the oxide is correctly cleaned up and the carbon black back
coating is removed and disposed of. In its deteriorated
condition, the degraded carbon black back coating provides a
substantial seed bed for moisture attraction, retention, and the
production of other chemicals resulting in the rapid growth of mold
and fungus along with many other major tape problems. These chemical
facts are readily apparent to anyone who does chemical and biological
laboratory research studies of the tape's total chemistry and its
various interrelated problems. I do have eye opening highly magnified
pictures of these tape deterioration facts and activities. They are
included in a paper I wrote in conjunction with many first rate
forensic chemists who completely analyzed the tape's chemical issues
and who then wrote up many superb scientific chemical reports on the
tape deterioration matters. But there is a communication difficulty
because the lab work is very technical. The lab reports go on for
hundreds of pages written up in chemical jargon terminology. This
cannot be readily or correctly boiled down to either sound bites or
plain English without falsifying, by oversimplification, this high
level detailed scientific information. Thus these definitive
chemical reports are not easily communicated, known or correctly
understood by lay persons who do not have a scientific and chemical
background.
I discovered and proved in the chemical lab that by a new, proper,
and sophisticated cleaning of both tape surfaces, one can get rid of
the moisture seed bed, mold, fungus, and other tape problems, thereby
restoring the tape in a highly effective and safe manner. Most
important of all, when the tapes are properly handled, their overt
behavioral response is highly positive with superb performance in
every department. Unfortunately, it is too a long story for this
short reply. Perhaps someday, your tapes can be restored with the new
better methods, provided the mold and fungus has not advanced too far
in their bacterial attack upon your tapes.
You mentioned a "water leak" but do not say if this water leak is from
tap water, rain water, or ground water. Tap water usually has
Chlorine in it which kills many kinds of bacterial and
other bad substances. Rain water (or distilled water) does not have
Chlorine in it, so mold and fungus can thus grow more rapidly in it if
a tape gets wet from rain or pure distilled water. Worse still is
ground or waste water which does not have Chlorine and has even more
debris and other unwanted chemical stuff in it. So the kind of water
and what is in the water or not is very important.
I am very concerned about your personal safety in handling these tapes
as some kinds of mold and fungus are a deadly poison. Be sure to wear
a mask, rubber gloves, and take other precautions. Also if the mold or
fungus gets loose in a state of spore reproduction, it can spread to
other places, tapes , etc and infect them, causing major infestation
problems. If you really want to know, go to a biologist, get him to
take a sample, grow a culture, do tests, and find out exactly what it
is. Maybe you are safe and OK, but maybe not. One should check
things out in the lab rather than just make guesses. Also mold and
fungus can go into a dormant state for a time and then have a spore
explosion if it gets the water or moisture it needs for its
reproduction purposes. The material you are dealing with may be
harmless and actually dead or it could be just in a dormant state that
is potentially dangerous.
The microscope needed for a good look at your tapes requires
considerable magnification horsepower. When carefully used by a
scientifically educated, trained, experienced, knowing mind with a
sharp eye for details then one will fully and correctly understand all
that is going on. As for magnification, special viewing techniques
are needed along with a microscope of at least 800 power to start
really seeing anything of importance. If you want to get down to the
molecular, atomic, or cell level, use 10,000 times magnification. If
you go higher to 20,000 times magnification, it really gets exciting
by going way down to the nitty gritty. The extraordinary universe of
extremely small chemical realities is most interesting and vitally
important. The chemical consequences of very small things are huge for
nearly everything. Its shocking as well as depressing that chemistry
is largely ignored, misunderstood, or badly distorted these days,
especially by self appointed "experts" with made up theories and blind
beliefs in wrong dogmatic views that do not have a factual or
scientific leg to stand on. Much of it is just mere words. If one
wants chemical and scientific facts, truth, and genuine comprehension,
one has to be both able and willing to dig deep for it over time.
Carefully read the relevant chemical lab reports on tape issues with
focused concentration and strict attention to all details. Use
critical thinking skills and scientific methods to develop a full
clear systematic scientific laboratory understanding of all that is
there. It is extremely hard, slow, demanding and painstaking work
to do this, but it is the only way to go if one wants knowledge
instead of an endless parade of mere mistaken opinions that are not up
to par.
Good luck in safely fixing your tapes.
Charlie Richardson
On Jan 29, 2009, at 12:58 PM, Trey Bunn wrote:
> I'm currently going through several boxes of reel to reel tapes (some
> acetate, some polyester) that may have been exposed to mold. There
> was a water leak where they were stored, and some of the boxes got
> slightly wet, so we're checking them to see if they're okay or not.
> So far, I've only seen mold on one of the boxes (the tape box, that
> is, not the larger cardboard box holding all of the tapes), and some
> of that got onto the outer layer of tape. The other tapes appear to
> be somewhat dirty and poorly packed in some cases, but as far as I can
> tell, no mold. I've been using a small brush to gently dust off what
> I've been finding, and my assumption is that if it brushes off easily,
> it's just dust, and mold would adhere more stubbornly.
>
> Am I right about this? It's been a couple of years since I've seen
> truly moldy tapes, so I want to make sure I'm not overlooking
> something. If I look at these under a microscope, what magnification
> do I need to use in order to see actual spores (if they're there)?
> It's a little difficult going through these because it's apparent that
> prior to two or three years ago, these tapes were not stored in ideal
> conditions. (Which of course means they might have mold on them from
> years ago and not this recent water incident.)
>
>
> ---------
> Trey Bunn
> Audiovisual Conservator
> Emory University Libraries
> Preservation Office
> Atlanta, GA
> 404-727-4894
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