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"Legal" or not, they're still readily available from the usual sources and I do keep one near the more-experimental of the 3D printers.

For those who aren't familiar, they're more-or-less a firework: Cardboard shell with redundant fuses wrapped around it to activate a charge inside, and with fire-putter-outer powder (IIRC sodium bicarb, but maybe something else) instead of stars. This whole thing is then wrapped in thin plastic.

Operation is simple: Fuse lights, because fire. It burns fast, by design. It explodes. The area is covered in powder.

It might even work. (Might make things worse, too, but things are already awful by this point.)

[petesergeant]

> For those who aren't familiar, they're more-or-less a firework

There's something beautifully, wonderfully Thai about creating fireworks to throw at fires. Also, this video: https://www.elidefire.com/performance-testing

[kragen]

that's brilliant! i'd assumed it was monoammonium phosphate. i'd much rather cover my electronics in sodium carbonate than in phosphoric acid

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Your comment encouraged me to look. It appears I my memory was wrong. I shall thus write about that.

I, a dumb consumer, conflated my singular experience with actually-using a fire extinguisher (which was full of sodium bicarb, and this was important to determine immediately after use because food was involved nearby, on a holiday, with lots of people to feed) to actually-extinguish a fire one time many years ago with the contents of the AFO fireball "percussive fire alert" widget that I have in the printing room.

(FWIW: That actually-used fire extinguisher was from Kidde, and I trust its CAS-numbered labelling.)

The AFO fireball widget here doesn't really say what it has inside: The printing on the plastic wrapper just says that it is "filled up with harmless Environmental powder(91/155EEC)" [sic] which does not seem to mean anything by itself.

Thanks, Elbonia.

All barely-reliable references I can find (and all of which are vague) for the AFO device's actual contents point to monoammonium phosphate, which I discovered even while not using that compound as a search time.

And that's not so good for electronics.

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But realistically, in the event of a fire that would actually set this thing off: The electronics are mostly toast anyway. Some may survive, some may not. Some may seem to survive but fail soon after, like the lifespan got shortened.

I've spent some time doing fire cleanup and restoration work. I've tried to rescue a fair number of electronic things that were on their way to the dumpster. It was mostly disappointment, interspersed with only occasional moments of seemingly-brief joy.

And that was actually a thing I considered of when I put this next to my printer a few years ago: I reasoned at that time that this will probably only activate if the bench (or room) is properly-aflame, but that it might help reduce total losses if it does activate.

The best case is that the printers (and other electronics) will get covered, nearly-enough, by the replacement-value rider on the insurance of my home's contents. They're all getting dumpstered and replaced with a check that should be in the right ballpark, and I can buy/built them again.

I also reasoned that the explosive fireball might buy a enough time to ultimately save the house that I'm in, so that added to its positivity. And that it might alert me if my usual smoke alarms did not: If I were sleeping or something, then a fucking explosion might wake me up in ways that loud high-frequency beeping might not.

But mostly, I reasoned that it might help save the cat from a printer fire, and that big dumb expensive cat is very important to me for all kinds of reasons.

So I still keep the firebomb near the experimental printer.

And like I said: Maybe it helps, and maybe it makes it worse. (I can't predict that without testing, but testing was is beyond my means. There's plenty of video of these things behaving well, and also of them behaving badly, but I'm not aware of anyone testing such a device with specifically a thing like a printer fire on a cluttered bench. I can imagine quite a lot, but that's not testing.)

[kragen]

haha, this is awesome

yeah, map is good stuff, but not great for electronics

i am not an expert but i think the concern with map on electronics is not so much that the phosphoric acid will eat them (if they're hot enough to unleash the ammonia, as you said, they're toast) but more that it will dissolve in the water from the firehose to form a fairly acidic solution that may still corrode the electronics