Re: [ARSCLIST] powder-like substance from open reel tapes

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

Jeff:

RTI makes a number of tape cleaning machines but I believe they cost around
$8,000 to $12,000 and I don't know if they make anything for audio tape.
They are also basically designed for recycling and may be problematic to use
for seriously compromised or decaying tapes.

We have a cleaner for audio tape but ours is custom and cost around $40,000.
You should be able to do an "ok" job by having an engineer attach some
tissue stations on an old deck.  You might try picking up an old pancake
winder as it has a lot of deck space you can work with.  Just make sure the
unit you use has variable speed and tension controls.  You can clean at
greater than play speed but you really don't want to risk cleaning at a fast
rewind speed and full tension if the tape is in bad shape.

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 Jeff Kane
> Sent: Wednesday, September 29, 2004 12:55 PM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] powder-like substance from open reel tapes
>
>
> Are any standalone machines available for tape cleaning that don't cost a
> fortune?
>
>
>
>
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx] On Behalf Of Peter@xxxxxxxxxxxxx
> Sent: Wednesday, September 29, 2004 11:21 AM
> To: ARSCLIST@xxxxxxxxxxxx
> Subject: Re: [ARSCLIST] powder-like substance from open reel tapes
>
> John:
>
> If you wipe the tapes, two tissues that are non-destructive are pellon
> (available on rolls if you want to set up a semi-automated or automated
> system) or Kimwipes EX-L from Kimberly-Clark (if you do the work by hand).
>
> Burnishing is usually done by running the tape past a specially
> constructed
> post on a winding mechanism.  Burnishing, when combined with a
> tissue wipe,
> greatly increases the effectiveness of the cleaning process but there are
> some specific cautions: Never run a tape over a burnishing post
> if the tape
> exhibits 1) visible edge damage, 2) a brittle acetate base, 3)loops or
> cinches in the tape pack or 4)has splices of unconfirmed integrity.
> Burnishing tapes with these sorts of problems can cause serious damage.
>
> Burnishing got a very bad reputation back in the 70's when a company was
> selling cleaning machines that used razor blades.  Further
> research by NASA,
> 3M and Grumman came up with much safer and more effective burnishing
> mechanisms that first used tungsten-carbide and ,later, sapphire.
>  The posts
> have to be ground and polished to fairly precise specifications,
> need to be
> positioned to intersect the tape within a limited range of angles and must
> be maintained without any scratches or chipping to be safe.  If
> you are not
> very familiar with burnishing tapes, it is usually best to limit
> yourself to
> the less-effective tissue wipe only.
>
> 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 John Loy
> > Sent: Wednesday, September 29, 2004 9:56 AM
> > To: ARSCLIST@xxxxxxxxxxxx
> > Subject: Re: [ARSCLIST] powder-like substance from open reel tapes
> >
> >
> > Thank you all,
> > For you timely and in-depth responses. Peter your suggestion I believe
> > is the closest to what I have encountered. The tapes I have show no
> > physical or audible signs of sticky-shed syndrome. The tapes have also
> > been cleaned of mold and stored properly in a humid and temperature
> > controlled environment for some time. Most of these tapes are form the
> > early 70's and in my experience that is just a little before sticky
> > shed problems started occuring.The main indication that it may be a
> > polyester chemical reminant is that the powder doesn't get on the tape
> > heads so much as the areas of the tape path that the back of the tape
> > comes in contact with. I will start wiping or burnishing the offending
> > tapes before playback to see if it helps and of course I will keep you
> > all updated. Once again thanks for your help and any other suggestions
> > are welcome.
> > John A. Loy
> > Audio Preservation Engineer
> > Southern Folklife Collection
> > University of North Carolina at Chapel Hill
> >
> >
> >
> >
> >
> >
> >
> > Quoting "Peter@xxxxxxxxxxxxx" <lists@xxxxxxxxxxxxx>:
> >
> > > John:
> > >
> > > "Powder" on the surface of magnetic tapes has been identified in
> > > laboratory testing as: polyester from the base film (alternately
> > > identified as tri-mers), sodium or calcium residue from the magnetic
> > > pigment, surfactant residue from the manufacturing process, various
> > > fatty acids from the lubricant and flowering heads from mold.
> > >
> > > In most instances you can tell whether it is chemical residue or
> > > mold by the visible pattern on the tape surface PRIOR to running the
> > > tape.  Mold has a tendency to appear as round(ish) patches or thin
> > > threads.  The chemical residues have a tendency to collect in lines
> > > on the edges of popped strands following a strand or group of
> > > strands around part of the curve of the tape pack.
> > >
> > > Mold will contaminate your machinery and can be a serious health
> > > hazard.
> > > Non of the other chemical residues has been identified as being
> > > toxic but I have known operators to get headaches when they became
> > > too inquisitive and ended up with a face full of the powder.
> > >
> > > Neither chemical decontamination nor baking work well at removing
> > > the powder residues prior to playback and baking can actually
> > > increase the amount of
> > > powder on the tape surface.   Tissue wiping or burnishing will
> > > usually
> > > remove sufficient powder to allow uncompromised playback but the
> > > powder will often re-appear after a few days or weeks.
> > >
> > > If your tapes have been very cold, you can sometimes get long
> > > crystals of lubricant on the tape surface.  These crystals can be
> > > re-absorbed into the tape by gentle heating but this is a very
> > > different phenomena than the "powder" residues.
> > >
> > > 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 John Loy
> > > > Sent: Tuesday, September 28, 2004 3:40 PM
> > > > To: ARSCLIST@xxxxxxxxxxxx
> > > > Subject: [ARSCLIST] powder-like substance from open reel tapes
> > > >
> > > >
> > > > I was wondering if anyone had experienced a powderlike substance
> > > from
> > > > open reel tapes from the early to mid 1970's. The brand of tapes
> > > are
> > > > TDK. The powder has been gumming up the machine's transport yet
> > > > has
> > > not
> > > > impeded play or audio quality. When I go to rewind a tape however,
> > > it
> > > > slows the machine and prevents a full rewind at which time I have
> > > to
> > > > clean the machine. The powder is a yellowish-brown and while it is
> > > on
> > > > the guides and heads of the machine looks organized but scrapes
> > > off
> > > > into a power. If you have heard of or experienced this problem
> > > please
> > > > respond and let me know what I can do about it or what effect it
> > > may
> > > > have on my machines or the tapes in a long term storage situation.
> > > > Please ONLY helpful, polite inquiries.
> > > >
> > > >
> > > >
> > > >   thanks,
> > > > John A. Loy
> > > > Audio Preservation Engineer
> > > > Southern Folklife Collection
> > > > UNC Chapel Hill
> > > >
> > >
> >
>