I sort of feel bad about raining on the parade of the person distilling isopropanol in his garage earlier, but it really is dangerous.

But most of us chemists also need to be reminded of it. To the point that someone had to write a paper whose entire point is “don’t distill isopropanol”.

Please, don’t do this thing.

The issue with isopropanol peroxide formation is that exposing it to air – even when just using it, like when you’re cleaning parts – starts the process. The air in the head space of your containers is also enough to form them over time. You don’t necessarily need to see solids in the containers for it to be dangerous, since they’ll crystallize out as you concentrate the solution during distillation.

It’s also a numbers game. It probably won’t explode the first time you do it. But there’s a chance each time. Do it enough, and you’ll have an incident.

There are chemical reductants that can clear peroxides. For industrial scale isopropanol distillation, I’m not sure what they use. It may be that they just never distill down to the point that peroxides concentrate to a dangerous level.

I love EnF. But I assure you, organic peroxide formers are scarier.

No no no no no.

I’m a chemist. Organic chemistry PhD, now a process chemist in the industry. I do this for a living. Do not distill isopropanol that’s been exposed to air for any meaningful length of time.

Isopropanol slowly reacts with oxygen in the air to generate peroxides that, when you concentrate them down, EXPLODE. Source. Sorry, not an open access journal. But please take my word for it.

Unless you have a way of confirming the peroxide levels in your isopropanol are near zero, do not concentrate it down by distillation. You’ll blow up your glassware, which will probably expose what you’re distilling to your heat source, which will generate a secondary fireball.

PLEASE do not do this.

Admission: I stole it.

qntm’s cool science fiction stories are my favorite.

Worse: your sleeper ship arrives at what should be a pristine planet. But FTL capable ships beat you there. And they ruined the planet over a few thousand years. And now they’re sending out refugee ships of their own.

I work a 9ish-to-5ish in a science field, salaried. Nobody really cares when I arrive or when I leave, as long as the work gets done. Sometimes science stuff goes off the rails and I have to arrive early or stay late, but I keep track of my hours and arrive a little early or leave a little early on other days to compensate.

I mean, it took four years of college and more than six of a PhD to get to this point, which stunk. But now I can monitor my chemicals stirring in a flask for a few minutes while hanging out on my phone, which is nice.

Hopefully not as a bunch of really good question posts full of mod-deleted answers.

The labrats subreddit was kinda fun. I’m a chemist, but the chemistry subreddit was overwhelmed by people asking for homework advice, showing off bad caffeine tattoos, and getting upset when they couldn’t talk about drugs or explosives.

Yeah, that sounds like seizing Russian assets and selling them to the west with more steps.

The axe forgets, the stump remembers

I’m late to the party but I use a WhamBam build surface on my Ender 3 V2. Absolutely a game changer. Wipe it down with high-percent isopropanol or acetone between prints and it works every time. Sticks like glue when hot and just pops off with zero effort once it cools down.

Not affiliated, just love the thing. https://www.whambamsystems.com/products/235-x-235-kit-with-pre-installed-pex-build-surface

I feel like I’m missing something with Connections. Like, the conceit of the game is that there are multiple potentially valid groupings and you have to figure out the right ones. But I always feel cheated when I guess seemingly valid but incorrect groups. As if I’ve lost a “guess what I’m thinking” game, not a real puzzle.

Or am I just really bad at this game?

Beats me. I’m just a chemist who managed my facility’s NMR magnets (built like MRIs but with different electronics for chemical analysis) for a few years. We had to pull some stunts to keep those magnets alive sometimes, but it was always a matter of how soon, not if, a shipment of cryogens would arrive. Can’t imagine trying to keep MRIs from quenching in a war zone.

No idea, but if it were up to me I’d spend that rationed power on ventilators and such keeping patients alive. Losing cryogens stinks, but you can top them off without any power as long as you have stock or deliveries. And I’d rather a magnet quench than have to explain to a dead person’s family that their loved one’s life was less valuable than some helium and a chunk of ceramic.

The cryogens boil off at a pretty consistent rate no matter what, but the recovery/recompression systems do require power. So once power is cut, any boil off isn’t recovered.

Superconducting magnets (like in MRIs) can run effectively forever when at the right temperature. Turning them off requires a complex process of draining off that current slowly and carefully so that the magnet isn’t damaged. Hard to do on a normal day, and profoundly harder if there’s no power.

I think the point is that even by the standards of his time, he was horrible. And that was an era where a common legal execution method was strapping you to a wagon wheel and beating you to death over the course of an hour. He was horrible compared even to that.

I appreciate your thorough response, but I think it’s clear that “maximize individual freedom” is a BS marketing phrase given how much nuance you had to use when rejecting the “freedoms” I proposed.

But also. No problem with coercing workers to do 80 hour weeks? I don’t think you’ve ever been in a situation where someone had that kind of power over you.

And selling junk but “safe” medicine is as dangerous as selling cyanide labeled as aspirin. Or are you content suing the drug company after your kid’s asthma rescue inhaler was actually just full of nothing and they asphyxiate to death?

You’re forcing a black-and-white dichotomy where one does not exist, which is a nice oversimplification that’s the exact sort of thing I’m talking about.

Everyone loves freedom! Like the freedom to:

• pay a child to work in a mine
• schedule workers for 80+ hours a week
• drive without speed limits
• use as much water out of the local river as desired
• dump waste into that same river
• sell unregulated, untested medicine

So obviously there are “freedoms” that mainly serve to infringe on the actual freedoms of others. Those just happen to be the ones that libertarians don’t talk about so much but are really what they’re after.