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Joined 1 year ago
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Cake day: July 15th, 2023

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  • 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.



  • 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.




  • At work, my work PC laptop drives two 1080p monitors. I don’t keep it open to use the onboard one because Windows is so terrible at handling displays of different sizes, and the fans run so much when driving three displays that I think it could take off my desk. So I know what you’re talking about.

    But. Have you ever used a Mac with two displays? A current-gen MacBook Air will drive a 6K@60Hz and a 5K@60Hz display when closed, and it’ll do it silently. Or both displays at “only” 4K if you want to crank the refrsh rate to over 100Hz. You think that’s not enough for the least expensive laptop they sell?

    I’m really tired of people who don’t know what they’re capable of telling me why I shouldn’t enjoy using my computer.



  • limit it

    There isn’t some software limitation here. It’s more that they only put two display controllers in the base level M-series chips. The vast, vast majority of users will have at most two displays. Putting more display controllers would add (minimal, but real) cost and complexity that most people won’t benefit from at all.

    On the current gen base level chips, you can have one external display plus the onboard one, or close the laptop and have two externals. Seems like plenty to me for the cheapest option.