On 1/10/19 10:37 AM, Ralph Mowery wrote:
In article -
september.org, says...

Don't use rubbing alcohol, it contains oil. Vodka is fine.
Clean the pinch wheels as well. All must be bone dry before
putting a tape in.

The heads are metal. No worries about hardening. Who told you
there was oil in rubbing alcohol? It's alcohol and water.
Period.


Heads have some insulating material imbedded. Real rubbing alcohol
is supposed to have oil to prevent skin drying too much. Most
don't. Isopropyl or ethyl cleans heads.



Rubbing alcohol seems to be a gernetic term by many.

One form is about 70% alcohol and some oils and water.

You can buy some that is about 90% alcohol and 10 % water with no
other oils in it. I have some here labled 91 % and some labled 99%.
They are isoprople alcohol and not labled rubbing alcohol. Alcohol
absorbs water from the atmosphere so before long the 99% will be much
less if open to the air.

Xylene was used at one time to clean the tape machinery. I am not
sure if it is in the stores any more or not.


Some rubbing alcohol is 80% isopropyl and 20% water. That has very
different properties, and will craze acrylics instantaneously. It also
leaves residues that cause enormous amounts of 1/f noise in front end
circuits.

Everclear is much better controlled.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net