1y ago

What happened to denatured alcohol?

I'm in US-GA and I cannot find denatured alcohol locally. WTF happened? I need something 100% alcohol for cleaning electronics.

38 comments

"Denatured" alcohol is just alcohol with undrinkable junk in it. Electronics grade alcohol doesn't need to be denatured, you need at least 99.5% purity instead (i.e. 0.5% or less water).
If you can't find it whatsoever, you can make it at home, from 96% (azeotropic) alcohol. Just add quicklime and let it soak that humidity. Warning: the reaction produces heat and alcohol is highly flammable, so only add a tiny bit of quicklime each time.
Source: I've worked in a lab owned by cheap fucks who expected us to conduct organic chemistry reactions with 96% alcohol. Had to improvise.

You can not really have 100% alcohol. It's really hard to get the last few percent of water out of it. Destillation is useless at that percentage and drying agents are used, but even they can't get all water out. Denatured just means that there is a bitter tasting chemical mixed in so it won't be drunken by those wanting to avoid alcohol taxes.
- that's fair enough. It's my bad for assuming it was 100%, I just assumed that if it wasn't 100% it would have said so on the bottle. it's just denatured alcohol as you would have(in the past) bought from the hardware store.
- That's mostly correct but I don't think it's entirely accurate. Distillation is useless at the azeotropic point but ternary mixtures are used to break the azeotrope. Once you move past the azeotrope you can continue distillation to high purity. You could also do pressure swing distillation but my guess (even though I'm not exactly a chemical engineer doing unit operations for a living) is that it wouldn't be economical. Of course, getting "100%" pure anything is really a different story...
  
  I think the point that it's not 100% is fair. It's just hardware store denatured alcohol and I assumed it was 100% since every other alcohol bottle either says proof or %, which was a mistake on my part regardless of whether it is actually 100% or not. It has always worked better for me than 91% isopropyl though and was the only other thing available.

I just want to compliment your use of ISO 3166-2
- Thanks, but I was unaware. I was just copying what I've seen elsewhere.
  
  Often you'll get people just writing GA which is ambiguous since it could equally apply to Gabon (Africa) or other places. A bit of a pet peeve of mine. It's a good habit, in my opinion, to always prefix the country code.

It's still in stores by me, but for some reason they changed the name to "fuel" or "marine stove fuel". I had to ask last time I went because I couldn't find it either.

I normally use isopropyl alcohol, it's actually a common use for it and you can find anhydrous isopropyl specifically for that purpose;
Example; https://www.amazon.com/MG-Chemicals-Isopropyl-Alcohol-Cleaner/dp/B078C8JYVV/ref=sr_1_1
Anhydrous isopropyl cleans rosin flux quite well, but you can add an extra step of using electical contatact cleaner.
Example; https://www.amazon.com/CRC-Industries-Inc-Electronic-Cleaner/dp/B00WJ9J5T2/ref=sr_1_21

You generally have to ask at the pharmacy desk since they keep it behind the counter.
- God, I hope that there aren't people trying to drink denatured alcohol.
  
  Just think about the most average person you know, and then remember that 50% of the population is dumber than that person. Yes someone has tried to drink it, and that is part of why its behind the counter.

Everclear?
- Not denatured but equally as ethanol. The only difference is you can occasionally take a sip of everclear
  
  Some states (like Michigan, for example), Everclear is only 75.5%. 151 proof is the legal limit for some dumb reason.

38 comments