[QuadList] Toluene

Thu Jan 14 19:32:28 CST 2010

Xylene, Toluene, Trichloretylene all this  stuff will give ya cancer  or 
drop your liver out of  your body be careful my friends!

ed#

In a message dated 1/14/2010 3:55:53 P.M. US Mountain Standard Time,  
park at videopark.com writes:

A couple  of points about head clogs.  

Oxide and binder comes off tape. Even if you look at an audio machine,  you 
can see oxide/binder on the heads and guides that came from the oxide side  
of the tape.

We have found that baking the tape (both audio and video) lessens or  
eliminates oxide and backcoating shedding (SSS - Sticky Shed Syndrome). SSS is  
caused by absorption of moisture into the binder of the tape,  making it 
sticky.

Yes, you need to clean the heads on a quad to remove the oxide layer.  When 
cleaning, you can see the oxide on your cleaning cloth. The oxide and  
binder material would short out the gap of the head or lessen its penetration  
into the tape due to buildup on the head surface.

The official Amex Head Cleaner was made from Xylene, not Toluene.

"The recommended solvent is Ampex Head Cleaner (Cat 087-007) which is  
composed of 98%  and a dash of "Kodaflow", which is a wetting agent  intended to 
enhance the flow of the solvent in restricted areas."

I  understand the TCE is to speed up evaporation. I don't remember  seeing 
any other chemical recommended by Ampex. Alcohol was the suggestion for  
cleaning the pinch roller. 

In modern VTRs like Digital Betacam that uses metal  tape, a cleaning tape 
is necessary to remove metal particles that get imbedded  in the heads since 
regular chemistry will not dissolve the metal particles.  Sony recommends 
using a cleaning tape for five seconds every 50 hours of  use.

Tape binders were/are made from polymers like polyvinyl  chloride, 
polyurethane resin and a copolymer of vinylidene chloride and  acrylonitrile, 
polyester urethane and the  like. I don't think any tape ever used Latex (rubber) 
as a  binder.

The old "thumbnail" trick on Quad was to loosen any foreign matter and  the 
14,000 rpm speed of the head would throw it off.

The 3M tape reels that had the foam on one flange had a problem of glue  
migrating through the foam and onto the tape. The glue did not come from the  
tape since after transferring the tape to a clean reel, the reel remained  
clean.

Best,
Park

C. Park Seward
Visit us: _http://www.videopark.com_ (http://www.videopark.com/) 

On Jan 14, 2010, at 12:30 PM, _georgenann at aol.com_ 
(mailto:georgenann at aol.com)  wrote:

I think there are many  people who are under the impression that "Head 
Clogs" come from oxide being  stuck in the gap of the heads.

I'm not sure this is the case.  There may be some instances of  this, but 
one of the common cures for an "On Air" head clog is putting your  thumbnail 
against the head, which works most of the time.  Seems to me  that would 
tend to push anything into the head, not out of it.

I think it is more a case of the latex binder oozing from the tape  and 
sticking to the head rim, causing "Rim Buildup" and keeping the tape  away from 
the head.

One of the other "Cures" for this is squirting Freon (TF) into the head  
while it is running. In this case, Freon is a refrigerant and due to the  high 
speed of the head immediately freezes the latex and it breaks off,  there 
is such a small amount of it you would hardly notice it, thereby  relieving 
the problem.

This "Oozing" of the latex binder has become quite obvious over the  past 
number of years with the older 2" tapes.  It is all over the  place.  In a 
few minutes of playing a tape, there may be a buildup of  this latex on the 
audio stack, full erase head, (Don't forget that is on the  back of the tape) 
fixed guides and all over the vac cols, stuck to the glass  and the entrance 
and exit guides thereof.  This will cause the machine  to just STOP!  This 
is also a big problem on 2000's and 1200's.   One can actually feel the 
stuff, even on the head wheel where it causes  "Head Clogs". In the AVR-1's one 
can also feel the stuff on the glass  in the vac cols. 

The only thing to do is stop and clean the stuff off of  everything.

Years ago, I thought I would try cleaning it up with some "Rubber  Cement 
Thinner" which had been in a closet in one of the secretary's  offices. It 
did the trick. 

Later, one of my neighbors who worked for "Tessa Tape" in Middletown,  NY 
gave me some "Toluene" as they use it as a latex thinner in the  
manufacturing process.  It worked like a charm, it dissolved the  damn latex 
immediately. I was hooked on the stuff. I highly  recommend it to everyone.  It won't 
hurt anything on the machine, or  plastic, but I would keep it away from 
pucks as they are made of  rubber.  Also it is a good idea to use it in a well 
ventilated  area

The best way to clean the pimpled glasses in the vac _cols.is_ 
(http://cols.is/)  to really saturate  a cloth with Toluene and wash it out, floating 
the stuff away.  Also  the bottom edges of the entrance and exit guides of the 
vac cols need to be  done with a Q-Tip as small unseen bits of latex like 
to live in  there.

My test to assure that the latex is completely gone is to thread the  
machine up, put it in ready and manually turn the capstan both ways.The  whole 
thing, tape, and both reels should move freely, no sticking in  either 
direction and no "Squeaking".

Now the same problem and Toluene cure applies to everything up to and  
including the Digibetas.  The U-Matics seem to have a problem with tape  coming 
around the guide inside of the cassette (Just under the  cover) causing the 
tape to either slow down or come to a complete  stop.  A little Toluene on a 
Q-Tip at that guide will amaze you.   I also recommend cleaning the tape 
guides audio stacks, etc.  on the  1100's and 2000's and for that matter all 
machines,especially before  attempting to adjust the tape guides, you may 
save yourself a lot of  work.

I understand Toluene may be hard to obtain, as it may be considered a  
dangerous chemical.  At first I ordered a gallon from Cole-Parmer in  Chicago.  
They sent it in a glass gallon jug in a cardboard box -  Not a good idea.  
If someone dropped it they would have had to evacuate  the whole building 
after it got into the air conditioning system.   After that I bought it in pint 
cans at a True Value hardware store in Pa.,  right across the river from 
Port Jervis,NY. as it is a common paint  thinner.  (Home Depot doesn't carry 
it in NY, NJ, or Pa. nor does  Lowes.) It only costs about $3.50 or so, not 
bad for about $500.00  worth of "Ampex Head Cleaner." I have further learned 
that Pa. is  somewhat lax of the dangerous chemicals possibly due to the 
"Hot-Rod"  industry in that state.

Don't forget what Tri -  Nitro - Toluene will do for  you.

One day there was a delegation from Sony in the shop, shortly after the  
Digibetas arrived, we had a problem with heads and some of the guys were  
replacing them like hot cakes.  The toluene cured them, but they still  wanted 
to replace the heads, around 5 kb a pop.

One of the Sony guys was the head of the Sony Tape Plant in Ala.   When I 
told him about using Toluene, he hit the roof went into a  rage about how 
terrible it was, I was nuts, and on and on.

I asked him what the Zip code of the tape plant is, and he gave it to  me.  
Now there is a Web site called "Score Card", in which you put in a  Zip 
code and it will tell you who the polluters in that area are, and what  they 
are polluting with.  Well, it came up with the Sony Tape Plant as  being one 
of the top ten polluters in the country of Toluene. (  
_http://scorecard.org/env-releases/facility.tcl?tri_id=36301SNYMGHWY84_ 
(http://scorecard.org/env-releases/facility.tcl?tri_id=36301SNYMGHWY84) ).   I see now that they have 
changed to Cobalt as their major pollutant,  but 
(_http://oaspub.epa.gov/enviro/multisys2.get_list_tri?tri_fac_id=36301SNYMGHWY84)  tells_ 
(http://oaspub.epa.gov/enviro/multisys2.get_list_tri?tri_fac_id=36301SNYMGHWY84)%20tells) 
 me they still spew quite a bit of Toluene into the air. If  you think he 
was mad earlier in the day, you should have seen him after I  showed him 
that. Score Card also showed my neighbor's plant (Tessa  Tape) in Middletown, NY 
also as being in the top 10% of Touluene polluters  also.( see  
_http://scorecard.org/env-releases/facility.tcl?tri_id=10940TSTCKCROTT#major_chemical_re
leases_ 
(http://scorecard.org/env-releases/facility.tcl?tri_id=10940TSTCKCROTT#major_chemical_releases) )  The Middletown Tessa Tape plant has since 
shut down and moved to Ala.  because of the pollution laws

I recall times where there was some "Glue" stuck on the foam rubber  liners 
on some 1" tape reels.  I wonder if this might also be leaking  latex 
binder from the tape, and not the glue holding the rubber to the  reels. It has 
also happened on some 2" reels with that type of liner.   Keeping in mind  
the amount of pressure on the wound tape and the  position of the "Glue"  (Not 
on the outer edges of the reel)  this  may be the case.

To top it all off, I was in the "Lab" across the street from CBS in the  
basement of the same building as Archives is located, bullshooting with one  
of the "Old Timers" who has been a senior engineer with the labs  since 
before anyone ever heard of video tape.  I mentioned my exploits  with Toluene 
and he was all over me telling me "That's How We Did it Years  Ago".

Was wondering if anyone else has had similar experiences??

73,

George Keller

=

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