Warning: FAFO is not a good way to learn about hydrofluoric acid.

Put some lye and aluminum foil in a cup without a handle.

Place a can over the cup with a small hole.

Wait a bit.

Light the hydrogen.

It will also hurt a lot if your finger is on top of the can when you light it because the can will simply dissapear for few seconds.

When working in a 100 degree server room on some solar batteries (AC was still being installed), sitting on the floor in your sweaty underwear and pants will give an 52V positive terminal a path to ground, though the contents of your underwear.

Unfortunately it was significantly on the pain side of the pain/pleasure scale of my nether region.

Not me but years ago the inorganic lab at my uni was tasked with measuring heavy metals in whale fat and did what they normally did back then to dislove test materials. Mix nitric acid and hydrocloric acid in some heavy duty pure quartz reagent tubes, put in sample and microwave.

Well. Turns out mixing triclyride (fat) with nitric acid and HCl as a catalyst makes nitroclyserine. And what does that do in a confined space and microwaved

It turns expensive heavy duty quartz tubes into expensive quartz dust and a fucked microwave.

I was trying to concentrate hydrochloric acid and had it in my boiling flask on a mantle. It was taking a while and I realized I hadn't added a stir-bar, so I tossed one in.

Then the superheated hydrochloric acid flash boiled and shot out of the flask like 8 feet in the air. Fortunately, I was outside.

body weight acts upon pool cover... i was a kid and almost drowned

I have a small concrete patio inside my house that is open so it's perfect for the pets (2 cats and 2 dogs) do poop and pee. I went traveling for 2 days and left the pets home and when I came back there was a lot of pee. I was out of cleaner and, since I'm a genius, I used BLEACH to clean the pet piss. Well, we had to evacuate because I just created a chemical weapon inside my house. Almost fainted.

I was seven.

My dad didn't give me a paintbrush so I made one by taping a chunk of styrofoam to a stick so I could paint my wooden airplane. It was oil based paint.

When my war vet father saw the styrofoam dissolving, he grabbed the can away from me, remembered the cigarette in his mouth, then shoved it back and made me put the lid on first.

And that was when I learned how to make nitro glycerine.

It gets quite hot but only makes nitrocellulose (aka guncotton) reliably with unbleached cotton, which you rarely find in clothes.

One of my favourites lines from "Ignition" by John Clark.

It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water-with which it reacts explosively.

I remember one time when I was a kid and had read something mentioning spark gap transmitters. I of course found a bit of wire (tie wire because that's what came to hand, not anything insulated) and a radio and was playing around with a 9v battery making little sparks by shorting it with the wire and hearing the radio crackle in response. What I then thought was that if the little battery was making a noticeable effect then a bigger battery would obviously be better.

I got one of the drill batteries and shorted that out with my bit of wire to make a better spark and proceeded to discover that resistive heating is a thing and thin tie wire connected even briefly to a high discharge battery will get very hot very quickly. I ended up with a nice blister line across my fingers and a scar for a few years showing the position I'd been holding the wire...

Early in my career I did tensile testing on adhesive coupons. I was running an experiment to simulate heating and cooling cycles on a bond. I had a nice big thermal chamber from the 1960’s, lined with heating elements (and undoubtedly asbestos), a big old dewar of liquid nitrogen, some thermocouples, and a PID controller the size of a German Shepherd.

Problem is, cold air sinks. My samples are sitting on the bottom of this huge chamber and their temperature is fluctuating wildly every time a bit of LN2 is added. The ancient PID controller cannot cope with my shitty test setup, it’s trying to turn on the damned heaters to control the temperature when I’m trying to go cold and this is a multi-hour test and I just want to go home.

But… I have a cardboard box. Nice, insulative cardboard, just the right height to get my samples off the floor of the chamber and into a zone where the temperature is more stable. I am brilliant! Cardboard box deployed, I can finally begin my thermal cycling.

I learned a few things that day:

• thermal cycles include both hot and cold phases
• the floor of the thermal chamber has much less temperature stability while cooling AND while heating
• specifically the floor contains a heating element and gets ridiculously hot
• cardboard combusts at a temperature much lower than you might expect
• opening the door of a smoking thermal chamber to investigate allows in a rush of oxygen
• rapid introduction of oxygen to a smoldering cardboard box leads to very large exciting pretty flames
• fire extinguishers leave a fine dust of particles all over everything that you will be cleaning up for MONTHS

Looks like when, as a child, I read on a bottle of bleach to avoid mixing it with acid. The first thing my dumb ass did was to look for a bottle of vinegar...

I don't know about best, but just happened to me: panicked and cleaned off grease from leather shoes with Windex.

What i tell you now must never be repeated to my parents. I will deny every word, except for the latter part that resulted in me burning a hole in the driveway since they already know about that.

When I was a teen, I spilled some gas on the concrete floor of the garage while filling up the lawn mower. I thought to myself, "What's the fastest way to clean this up?" Clearly the fastest option was to burn it. This did in fact work and produced a controllable flame, but I had neglected to move the closed plastic gas can away from the puddle of gasoline. As it turns out, plastic is made of flammable petrochemicals. The outside of it immediately caught on fire.

I realized that if the gas can lost structural integrity, gas would flood the garage floor, likely setting the whole structure ablaze. So, I picked up the flaming jug of death and ran out of the garage, setting it in the middle of the asphalt driveway downwind of any important structures. I now had the task of putting out a gasoline fire. How could I do this? Obviously, the best way to put out a fire is to spray it with a hose. So I grabbed the garden hose and aimed the nozzle at the melting jug of death.

This did not work. As it turns out, gasoline floats on water, and as such spraying water on a gasoline fire simply increases its surface area. It roared like a bonfire and the plastic can rapidly collapsed. Additionally, it turns out that asphalt is mainly composed of tar, which is a flammable petrochemical.

At some point I realized I had no idea what I was doing and called the fire department. By the time a fireman arrived, all that remained of the blaze was a smoking hole in the driveway the size of a small child, which was extinguished with a handheld chemical extinguisher.

My dad, at the time, was in charge of the safety training at the local chemical plant. My attempt to extinguish the flaming jug of death made an appearance in one of his PowerPoint slides as an example of what not to do with an oil fire.

I feel boring - only thing I ever had to realize that if you work with solvents with a boiling point close to body temperature and have them in a flask with a glass cork, you shouldn't hold the flask in your warm hands while waiting - because after a few minutes the glass cork flies off and you have to pay for it 😕

Girl in my chemistry class painted her face with silver nitrate (IIRC the chemical correctly; something used in photo development turns dark brown/black when exposed to sunlight) because she did not believe it would do anything once she went out into the sun.

She got sent home for being in black flace next period.

It's not really science-y, but expanding foam is a type of glue and will glue to everything it can. I got expanding foam everywhere including all over my hands for about a week. They were just crusty, not glued to stuff.