Re: [ARSCLIST] powdery substance on 2" tape

["Peter@xxxxxxxxxxxxx" <lists@xxxxxxxxxxxxx>]

Bob:

The cushion-flange glue problem only happened on 3M (Scotch) 1" and 2"
video.  Most cushioned reels are fine but, at one point, 3M subcontracted
out the cushion attachment part of the reel manufacture and the
subcontractor used the wrong glue.  Lucky for those on this list, the
problem never showed up on audio tape.

It is possible to remove the glue (we are processing about 1/2 a dozen
in-house right now) but it is a time-consuming and expensive process.


Peter Brothers
President
SPECS BROS., LLC
(201) 440-6589
www.specsbros.com

Restoration and Disaster Recovery Service Since 1983



> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx]On Behalf Of Robert Hodge
> Sent: Wednesday, April 20, 2005 2:13 PM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] powdery substance on 2" tape
>
>
> Hello,
>
> I have encountered 2 inch tape reels which had a foam backing glued to
> the insideof each flange. Scotch , I believe.
> Both the disintegration of the foam as well as breakdown of the
> adhesive will cause contamination of the tape. The foam residue comes
> off relatively easily- the glue is a first class horror as it leaches
> between the tape layers and makes any playback impossible..
> Check the inside flanges of your reels- if the foam is present,I'd
> recommend sending  the tape to a professional to decontaminate it -
> baking will be futile and will make the situation infinately worse!!
> My situation was dealt with simply by tossing the tape as it contained
> nothing worthy of preservation.
>
> I wish you luck !
>
> Bob Hodge
> Syracuse University Audio Archive
>
> >>> lists@xxxxxxxxxxxxx 4/20/2005 12:07:51 PM >>>
> Heath:
>
> The pictures are not that clear and it could well be fungus but the
> general
> shape of the "clumps" of contaminants are more consistent with other
> problems.  White powdery substance found on tape has been identified in
> the
> lab as a number of different compounds, other than fungus, including:
> cyclic
> tri-mers from the polyester, sodium or calcium impurities from the
> magnetic
> powder, various fatty acids or sterates from the lubricant and
> surfactants
> left over from the manufacturing process.
>
> Most fungus does not manifest as a "powdery substance" but as
> patterned
> colonies or thread-like groupings.  The fatty acids and sterates from
> the
> lubricant usually appear as distinct crystalline structures after the
> tape
> has had long-term exposure to very low temperatures and will usually
> sublime
> or be re-absorbed into the tape after exposure to room temperature for
> 24 to
> 48 hours.  A white powdery substance is most likely to be calcium,
> sodium or
> surfactant residue that has migrated to the tape surface.
>
> What temperature/humidity conditions were the tapes stored at and is
> the
> residue strictly "powdery" or does it show some crystalline or
> thread-like
> structure?
>
> If you do identify the contaminant as fungus, it is important to make
> sure
> the fungus is dormant before attempting to remove it.  Active fungus
> will
> tend to "smear" if wiped with pellon.  Dormant fungus will be much
> easier to
> remove.  Dormancy can be achieved by isolating the tape in an
> environment
> with a low RH (we prefer below 30%) for approximately one week.
>
> If the contaminant is not fungus, as I suspect from your description
> and the
> pictures, do not "bake" the tapes.  Baking will increase the presence
> of
> manufacturing residues on the tape surface rather than reduce them.
>
> The residues left over from manufacturing can be removed by wiping with
> a
> tissue.  Care must be taken, however, as the volume of these residues
> is
> often such that they will quickly clog the tissue and re-deposit on
> the
> tape.  Cleaning of these residues (and fungus) is more effective if
> both a
> tissue wipe and burnishing can be applied.  Also note that once the
> residues
> have begun to emerge from the tape, they will continue to emerge for a
> period of time.  Once the tape has been cleaned, it should be copied as
> soon
> as possible, before more residue can appear.
>
> Peter Brothers
> President
> SPECS BROS., LLC
> (201) 440-6589
> www.specsbros.com
>
> Restoration and Disaster Recovery Service Since 1983
>
> > -----Original Message-----
> > From: Association for Recorded Sound Discussion List
> > [mailto:ARSCLIST@xxxxxxx]On Behalf Of Heath Condiotte
> > Sent: Tuesday, April 19, 2005 2:24 PM
> > To: ARSCLIST@xxxxxxxxxxxx
> > Subject: [ARSCLIST] powdery substance on 2" tape
> >
> >
> > Hello all,
> >
> >
> http://img.photobucket.com/albums/v663/heath4242/whitepowderontape.jpg
>
> > http://img.photobucket.com/albums/v663/heath4242/whitepowderclose.jpg
>
> >
> > The above links point to two pictures of a reel that contains a
> powdery
> > substance we have never encountered before.  I'm wondering if any of
> you
> > have dealt with this and have any suggestions? Here are the
> pertinent
> > details:
> >
> > -Ampex 456 from circa 1977 (at least that was the record date--the
> stock
> > could be older)
> > -No apparrent water damage
> > -Tapes have been stored in a climate controlled, stable vault for at
> least
> > the past year.  Prior to that time, we do not know where these tapes
> were
> > located
> > -The white powder wipes off rather easily when touched
> > -The powder covers all edge surfaces of the tape--not just the
> openings in
> > the flange.  When the flange is removed, the substance is on the
> > entire edge
> > surface.
> >
> >
> > Would a pellon cleaning be a sufficient method of prepping these
> tapes for
> > back up? Or would more processes need to be performed? Our
> > caution is based
> > on our assumption that these tapes will need baking (they are from a
> > suspicious batch), and although we have treated mold and water
> > damaged tapes
> > before, this substance is new to us.
> >
> > Thanks in advance for any input
> >
> > Heath Condiotte
> > Audio Engineer
> > Xepa Digital
> > www.xepadigital.com
> > hcondiotte@xxxxxxxxxxxxxxx
> > (724)794-3686 phone
> > (724)794-3292 fax
> >
> >
>
>