wjm (01/06/83)
I'd like to flame again about the use of various types of chemical goop to
clean tape decks and their parts. As I said earlier there are only two
safe things to clean tape decks with: isopropyl alcohol and certain
halogenated hydrocarbons (specifically trichlorethane (used by Nortronics
in their tape head cleaner and trichlorotriflouroethane (a.k.a. Freon-TF
and Freon 113 (I think that's the number))).
NO OTHER COMPOUND SHOULD BE USED UNLESS SPECIFICALLY RECOMMENDED BY THE
MANUFACTURER OF YOUR TAPE DECK. USE OF OTHER SOLVENTS CAN DISSOLVE THE
ENCAPSULATING COMPOUND USED ON TAPE HEADS AND REQUIRE HEAD REPLACEMENT
WHICH IS BIG $$$.
In particular, I'd be VERY wary of lacquer thinner or acetone given their
nasty habits for dissolving plastics.
As for booze, ethanol itself is probably OK, but most firewater contains
other flavoring materials and coloring agents which could gum up the works.
Vodka is probably least damaging in this regard, but isopropyl alcohol is
a lot cheaper.
[ Aside to Dave Martindale ... I don't know a mail path to your machine
Thanks for the comment. Trichlorethylene has a double bond between its
two carbon atoms, hence the molecular formula
HClC = CCl2
whereas trichlorethane has a single bond between the carbons and two more
hydrogen atoms
H2ClC - CCl2H
(there are other arrangements for the three chlorine and three hydrogen atoms,
I don't remember which one corresponds to the commercial compound)
Trichlorethylene used to be widely used as a dry cleaning fluid until it was
found to be carcinogenic - I don't recommend its use on tape decks. ]
Personally, I use drugstore isopropyl alcohol to clean my deck. I'm of the
school that alcohol will not do substantial damage to pinch rollers.
As for demagnetizing, Greystroke's article yesterday sums up how heads get
magnetized and I'd like to reiterate his key point
ONCE A TAPE HAS BEEN DAMAGED BY PLAYING IT ON A DECK WITH MAGNETIZED HEADS
IT IS PERMANENTLY DAMAGED. DEMAGNETIZATION WILL NOT FIX THAT TAPE (although
it will prevent other tapes from meeting its fate).
Therefore, as part of a proper maintainence program, one should demagnetize
at least every 40-50 hours on newer decks (whose heads are more resistant
to magnetization) and every 10 to 20 hours on older equipment. If in doubt,
demagnetize since it will do no harm if done properly. Just remember to
remove the demagnetizer from the heads slowly and to take it across the
room before you turn it off (or use TDK's cassette on cassette decks).
End of flame.
Bill Mitchell
Bell Laboratories, Whippany
(whuxk!wjm)