Before trying to clean the mold off, make sure the tape is very dry and the
mold has been driven into dormancy.  Even when the tape has been removed
from the environment that caused the mold, it will still continue growing
using the moisture trapped in the tape itself.  Attempting to remove active
mold is very difficult and a wipe will often spread it over the surface
rather than removing it.

To drive the mold into dormancy, it is necessary to remove moisture from the
mold, itself, and the tape.  This can take up to 8 - 10 days of holding the
tape in a controlled environment of around 30% RH.  It can be done somewhat
faster at lower RH and can take quite a lot more time if the RH is higher.
(Note: baking is not recommended as, while it can sometimes work, it can
also cause problems with moldy tape- depending on the type and amount of
mold, baking can harden the mold-related residues and "bake" wraps

Once the surface mold is dormant, it becomes dry and brittle- thus it is
easier to wipe off and doesn't "smear".  After a dry wipe, go back and
inspect the tape surface to treat badly damaged/infected areas with your wet
wipe of choice.  Also note, removing the fungus from the surface of the tape
DOES NOT KILL THE FUNGUS.  If the tape is subject to high humidity
conditions after being cleaned, the rhizomes imbedded in the tape binder
will start growing fungus again fairly quickly.

The fungus can be killed with a wet-wipe of 111-Tri-chlor but this is a VERY
time-consuming process and, since Tri-chlor is a controlled substance, the
chemical is not readily available.

Of course, you can always send the tapes out and have someone else do them,
but labs like ours charge a fairly good amount to do fungus remediation. 

Peter Brothers
[log in to unmask]

Tape restoration and disaster recovery since 1983

-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Martin Fisher
Sent: Monday, July 09, 2007 3:52 PM
To: [log in to unmask]
Subject: [ARSCLIST] Moldy Tapes

Hi All,

Got two boxes of moldy (purty deep forest green) 1/4 inch reels (some
backcoated) that need to be cleaned up, transferred and reboxed.  Is there a
good method for physically getting the mold off the oxide layer that doesn't
involve foot by foot wiping?  Passing through a dry cloth gets the surface
stuff off but even two passes of wet/dry doesn't get the adhered layer off
the magnetic surface.