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.

It was a scan during upload to their cloud photos system. Everyone else does it on their servers, Apple was going to run the scan before so they didn’t have to ever have them. To not have images scanned before upload, a user would just not have to use their cloud photos service.

The messaging was really badly handled. They almost certainly just scan all the same photos on their servers instead now.

You should ask, like, any woman in your life.

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

It is infinitely remappable. To anything you can program in with a Shortcut, which is a ton of non-trivial stuff. Which they said explicitly.

So many people in this thread saying “who cares it’s just a button” without having any idea what it actually does.

Want the mute switch behavior? Well that’s the default thing the button does and you can use it without looking at it.

Want to program the button to do like literally anything? You can do that. For example:

• Launch the camera app, or any other app
• Control your smart home accessories
• Toggle Do Not Disturb, or another focus mode
• Run a command on a remote server via ssh
• Start recording audio in case you’re around cops doing cop stuff
• Or anything else you can program in with a Shortcut

Neat! How much do you figure it can hold up?