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Dave Platt[_2_] Dave Platt[_2_] is offline
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Default using acetone to clean audio cassette heads


In article ,
wrote:
On Thursday, 10 January 2019 04:12:57 UTC, The Real Bev wrote:


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


I forget the official standard for it, but it contains rather more than water & alcohol. Looked it up last year.


"Rubbing alcohol" is addressed by several different USP standards.

"Isopropyl Rubbing Alcohol USP" is defined as 70% isopropyl alcohol
(plus or minus a couple of percent) by volume, the remainder
"water, with or without suitable stabilizers, perfume oils, and color
additives certified by the FDA for use in drugs." So, even drugstore
isopropyl alcohol can have components other than alcohol and water.

"Rubbing Alcohol USP" (without the word "isopropyl") is ethanol,
water, denaturants (e.g. sucrose octaacetate or denatonium benzoate),
"with or without color additives, and perfume oils."

Some commercial rubbing alcohol used to contain lanolin, to help keep
the skin from drying out; I don't know if any still does.

If you don't see the term "USP" on the label, then whatever you're
buying may not comply with the USP standards I mentioned.

Outside the US things are even more complex; British "surgical
spirit" is methylated spirit (ethanol denatured with methanol),
castor oil, diethyl phthalate, and methyl salicylate ("wintergreen
oil").

(Relevant information cribbed from the Wikipedia article on rubbing
alcohol, and the newdruginfo.com links which cite the USP
definitions).

For electronics cleaning purposes such as tape-deck heads, I prefer to
buy technical-grade isopropyl alcohol. My local Frys carries the
Puretronics brand ($9/quart).