Isopropanol is never denatured because its not consumable by humans. Only materials that are consumable are denatured, and that is usually done by adding natural gasoline (pentanes) to make it poison, and this is usually used in the fuel industry for blending with gasoline. Ethanol (drinkable) is, indeed a maximum of 90% pure due to the azeotrope that is formed with ethanol and water that causes a pinch point and lack of ability to distill it into a more pure form. Distilling above 90% can be done by adding a third substance to get around the Azeotropic pinch point, or by use of sieves to absorb water.
Dr. William J. Schmidt (one of my Ph.D. is in Chemical Engineering) -----Original Message----- From: [email protected] <[email protected]> On Behalf Of John Marvin Sent: Wednesday, July 14, 2021 7:00 PM To: [email protected] Subject: Re: [Elecraft] 99.9 % alcohol Anything above 95% or so requires processes beyond just distillation, i.e. you are getting into the lab grade region. Prices usually go up significantly for that. Of course, in many states you can buy 190 proof Everclear (95% grain alcohol) at a liquor store. Might be easier to find than lab grade alcohol. One advantage is that since it is not denatured, the fumes are significantly less toxic. Since alcohol is hydrophilic, it helps to evaporate the water that makes up the rest of the alcohol mixture. I suspect that getting much above 90% doesn't yield significant improvement in evaporation time. But we obviously have examples here where using something higher than 90% would be more desirable if you are not spot cleaning and don't want to wait. Regards, John AC0ZG On 7/14/2021 5:41 PM, brianpepperdine brianpepperdine wrote: > I have no idea, obviously, what the USA market offers, but here we get > 99.9% (not 90%) isoprophyl alcohol. So much the better re. less residue of > course. > Admittedly it was a bit hard to get at the beginning of the pandemic > but that seemed resolved with a couple months. > > Ages past I had to ask the pharmacist for it and he decanted it from a > large bottle behind the counter into a small bottle for me. > He said you are either diabetic or into electronics, as I think that > was the main call for it. Largely they sold the smaller percentage > stuff for rubbing and sores. > Here is is stocked on the shelf now already packaged, in the first aid > area (right next to the alcohol swabs). > > If hard to find you might ask your pharmacist.. its possible they have > it behind the counter for the real need purposes, or he can suggest if he can > order-in. > You never know. I doubt at this time now that there is any real supply > shortage, IMHO" > > Brian VE3HI Toronto > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html Message delivered to > [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] -- This email has been checked for viruses by AVG. https://www.avg.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
