[QuadList] Toluene

[georgenann at aol.com]

I kind of remember being told that at the Ampex tape plant about 100 years or so ago, or was told that somewhere along the line. That's one reason I tried the rubber cement thinner in the first place.  And everything seemed to fall in place.

I appreciate the chemical info, but not based in chemestry it won't help much.  I wonder just what all the freon will do to you, CBS used about 5 gal every couple weeks.

I was very careful when using toluene around plastics, especially the tape cassettes, I experimented a good bit. It didn't seem to hurt it at all.  There may be some plastics which it will damage.

I have always been affraid of MEK, have been told many times, including by the Navy which banned it many years ago.

Mny Tnx for the input.

George











-----Original Message-----
From: Tim Vitale <tjvitale at ix.netcom.com>
To: 'Quad List' <quadlist at quadvideotapegroup.com>
Sent: Thu, Jan 14, 2010 7:03 pm
Subject: Re: [QuadList] Toluene


How did you identify the binder as latex rubber?  
Later videotape (1/2" R-2-R and later, for sure) used polyurethane as
he medium for the magnetic pigment (that what it's called) on an
ellulose acetate or polyester base.  Polyurethane degrades by
reaking off small chains (under acid hydrolysis) of the long urethane
olymers, which clump together as "gunk" that was known as the Sticky
hed Syndrome.  There will be magnetic pigment particles in the
stuff" stuck to the head, cap stands, guides and wheels.  The "stuff"
hould be nicely soluble in toluene.  However, toluene is quite toxic,
specially if you get it on your skin.  Toluene is a benzene ring
cancer causing) with a methyl group (CH3) on one of the six carbons
n the aromatic ring.
As a conservator with some age on me, I have been guilty of doing what
ou have done, and of holding your views.  We had a number deaths in
he field years ago that were attributed to solvent use, however, not
ust toluene use.  We, and I, are much more cautious now.  Toluene
oes work its way out of the systems in time
ttp://en.wikipedia.org/wiki/Toluene, but it is one of the slower
nes, if memory serves.
I'd use a solvent that does the job (maybe not as quickly or with more
lbow grease), but is less toxic, or one that is more easily removed
y the body's defenses.  I'd try acetone first, then methyl ethyl
etone (MEK).  They are both in the ketone group, which our body makes
hen burning fat under a low carbohydrate diet; you know, ketosis. You
an find all the above solvents (and many more) at Home Depot; even
oluene.  They generally run about $4-7 per quart.
There is a complex Teas solubility process that is used to estimate
olubility.  I can walk you through it, if you like.  I'll have to fax
ou some charts and diagrams.
BTW, toluene will go after quite a few plastics.  I would not consider
t safe for plastic-laden equipment.  Alcohols (specifically,
ropanol) are generally the only solvents that get a pass for use on
quipment.  
Best of luck...
Tim Vitale
aper, Photographs &
lectronic Media Conservator
igital Imaging & Facsimiles
ilm [Still] Migration to Digital Format
igital Imaging & Facsimiles
reservation Associates 
500 Park Avenue 
uite 123
meryville, CA 94608
510-594-8277
10-594-8799 fax 
tjvitale at ix.netcom.com
itale bio
ttp://videopreservation.conservation-us.org/tjv/vitale_1pg_bio.pdf
esume: see link in lower right corner of the URL above. 
lbumen Photography Website in 2000
http://albumen.conservation-us.org>
ideoPreservation Website in 2007
http://videopreservation.conservation-us.org>

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