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