Cleaning mirrors with alcohol.

Well after Dave Bonandrini mentioned an article in Photonics Spectra magazine concerning cleaning of optical mirrors and their stating that alcohol was not to be used, I contact them and asked for a copy.
I have the magazine and article now and have read it. The article was well written and by a professional optician and the cleaning methods were well described and did correspond to what I had learned in the past. Including the information on alcohol and aluminum. Their statement is "Because alcohol reacts with aluminum, it should never be used on protected or bare aluminum- coated mirrors.
Now this goes along with everything I have ever been told about alcohol. I do not use it on mirrors, but use Acetone instead or sometimes MEK. There are people that are still advocating the use of alcohol as a rinse for our mirrors, and this is why I am writing this thread.
Dave Bonandrini already mentioned this. I am just confirming his statements.

Floyd,

Interestingly, my father's Dynascope has instructions to use 100% Grain Alcohol only!

Is there a difference in the types of alcohol I wonder. Was Dave referring to denatured alcohol which is perhaps derrived from a different source or adulterated?

From Wikipedia---Denatured Alcohol: "ethanol with added adulterants that make it useless for consumption as an intoxicating beverage by rendering it toxic or extremely distasteful to drink, but still useful for industrial processes or as a household chemical. This is done in order to make it exempt from taxes that apply to potable alcohol.

There are diverse industrial uses for ethanol, and therefore literally hundreds of recipes for denaturing ethanol. Typical additives are methanol, isopropanol, methyl ethyl ketone, methyl isobutyl ketone, denatonium, and even aviation gasoline"!

Has Dave investigated Grain Alcohol? I mean, for mirrors of course!

Too bad you need a perscription to obtain it.

Gerald

I like Floyd and others have always used just the soap and water method to clean my mirrors. I also have always heard that you should never use alcohol on a mirror, and I don't. However when I got my new 20" Starmaster with a Zambuto mirror that has Nova coatings I was shocked to find that Steve Dobbs of Nova recommends using Isopropyl alcohol for "very dirty mirrors". I wonder why he would say that it is okay to use alcohol?

I have a 25-year old 10" classical cassegrain set (Coulter) that I have cleaned only three times since it was purchased in 1980. The procedure was the same - initial rinse with distilled water, wash with mild detergent/distilled water solution (no scrubbing, wiping - just soap action), and final thorough rinse in distilled water. Even if a few specs of dirt refuse to dislodge - leave them alone and don't try to scrub them off - it's not worth the wear on the mirror surface.
my 2cents.

Bob