OT: Cleaning video head on my Betamax VCR

[Thompson Freeman]

On 08/10/2008 02:44:05 AM, Tim wrote:
> On Sat, 2008-08-09 at 21:20 -0400, Matthew Saltzman wrote:
> > *Denatured* alcohol!
> 
> Yes.  For those unfamiliar with the term, the usual cleaning alcohols
> that you can buy are deliberately *poisoned* to stop people drinking
> them (go figure!).  I had to convince the local pharmacist to give me
> some untainted alcohol at one stage.  Later on, I had an even hard
> time
> convincing customs and excise to let me buy pure alcohol.  They only
> relented after telling them about how poisonous and dangerous the
> alternatives were.
> 
> That tainting is bad news for cleaning video and audio heads.  They
> can
> be used, if you're desperate, and you wipe things clean and dry,
> instead
> of just letting them evaporate.  They contain a variety of things 
> that
> you don't want left behind on the heads, and that's very easy to do.
> You're much better off finding something more appropriate.
> 
> Be especially careful cleaning anything plastic or rubber, solvents
> can
> destroy them.  Remember that on the audio heads, at least, the head
> block unit might have the magnetic part of the head embedded in a
> plastic material.
> 
> Do NOT use turps.
<<snip>>

I'm having a devil of a time following this thread with respect to the 
solvent. Not that I'm about to clean any betamax heads, or any magnetic 
tape heads soon, but with a background in chemistry...

Apparently, we also have some challenges with having different 
countries represented here, which also changes the underlying terms 
some. Note that I quickly checked the Wikipedia for reorientation.

Denatured alcohol is ethanol (the drinking type of alcohol) which is 
mixed with something to make it unpalatable to poisonous to drink. If 
memory serves, there are something like 200 additives approved for this 
purpose, ranging from methanol (wood alcohol) through aviation gas to 
some dyes. 

Rubbing alcohol was originally something like 70% (vol) ethanol plus or 
minus a good bit. In commerce, however, you are just as likely to find 
isopropyl alcohol as ethanol sold as rubbing alcohol. Since isopropyl 
is toxic, it is more likely to be a fairly simple solution of isopropyl 
alcohol and water. Here in the States, you can find the isopropyl 
rubbing alcohol at 90%, sold as an antiseptic. The bottle label I have 
indicates, but does not explicitely state, that the product contains 
only the alcohol and water. I don't know conditions 
elsewhere.

As solvents, it is my impression that isopropyl alcohol and ethanol are 
very similar. As such, I'm curious if the video engineers have tried 
it.