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.

TLDR for anyone reading: Do not do this!

There is a very well laid out reason by @becausechemistry@lemm.ee in this thread, but suffice to say this is dangerous to an extreme and is not worth the risk to save a little money.

How much $ you saving (or any other motivations)?

Don’t have frames of reference so perhaps what proportion less are you paying by doing this?

Assuming it’s no small sum/% given risks called out by you and a couple others. Glad you got a discussion going so you can give it all more thought!

Yo, this thread caught my eye, but because it’s deleted, it’s unclear exactly what it’s about. Can someone summarize exactly what I’m to avoid?

Do you take any steps to clean the wash before boiling it? Filtering or anything like that?

I've had some success using aluminum sulfate to precipitate resin out of the wash based on this guy's work: Recycle Isopropyl Alcohol FAST! | Recovering IPA From 3D Printer Resin Wash

I haven't tried distillation... as you say, it's risky.

What does your waste look like after distillation? And... what would you think about using an alcohol still for this, instead of lab glassware?

What I do is just expose the dirty isopropanol to sun or UV in general - the resin will precipitate. Then just filter it out and you have clean isopropanol.

Have you tried using typical water filters and letting the alcohol filter through? I suppose it wouldn't remain as pure as distilling, but might be mostly reusable while posing no immediate fire hazard.

It may be worthwhile checking this out as an alternative: https://hackaday.com/2022/10/12/toilet-paper-tube-pulls-dissolved-resin-from-ipa-cures-it-for-disposal/

A BIT?!!! oh fuck no

You deleted your comments but not the post 🤪