9 ms·

Lab explosions and accidents

145 points by epsylon 11y ago

weaksauce 11y ago
I'm almost glad I didn't pay more attention in chemistry class because I'm sure I'd do some of these blunders.
David 11y ago
In chemistry class in middle and high school, I thought all the safety precautions we took were stupid, given that we were using harmless chemicals to do harmless experiments. I wish this had been around, and it had been required reading--I would have all about that safety gear.
JabavuAdams 11y ago
Fantastic! I love reading accident reports, for some reason. There's so much practical knowledge contained in them.
brandmeyer 11y ago
Once upon a time, in the nuclear submarine navy, my shipmate tags out the ship's battery breaker. As part of the tagout, he checks that the ship's DC bus is deenergized - within the battery breaker box itself. During the check, he finds some voltage, which isn't entirely unexpected, since there is enough capacitance on the DC bus to hold it charged for a while. So he uses a specialized grounding probe - about 1/8" diameter copper rod with a reinforced handle - to discharge it. Unfortunately, he has misunderstood what was inside the breaker box and is actually shorting out the ship's main battery! This is a couple hundred volts DC, and a few thousand amp-hours of capacity, and it delivers enough current to instantly vaporized the grounding rod. He's knocked on his ass by the arc blast. Fortunately, he was correctly considering the box to be energized gear and was wearing a full set of PPE, suffering only minor flash damage to his eyes.
- jacquesm 11y ago
  Lucky guy, lucky too he used a relatively thin rod, a thicker one and it would have been quite a different ending. I did a similarly stupid thing one day. While repairing a clock for a display on a trade show I hooked the ground crocodile clamp of my scope to what I thought was the ground but which in fact was V- of the DC supply voltage of the neon light installation that was use to drive the display. I had a blind spot in the middle of my eyes for many days after that (and took out a fairly large chunk of the mains supply for the Eastern district of Amsterdam). The crocodile clamp totally disappeared, the scope, miraculously survived and wasn't even out of spec. Every time I use a crocodile clamp to hook it on to something I think back to that moment when the clamp makes contact and some part of me expects it to happen again.
  - brandmeyer 11y ago
    > I hooked the ground crocodile clamp of my scope to what I thought was the ground but which in fact was V- of the DC supply voltage of the neon light installation that was use to drive the display. Yeao! I own a couple of high-voltage differential probes for this very purpose. Even though most single-ended scope probes are rated to 300V Cat II, I won't go anywhere near main's power with them.
- CamperBob2 11y ago
  Pretty hard to top that. "I bought some fuming nitric acid on eBay and spilled it on the carpet. Dad was pissed." "I fused two screwdrivers together with a photoflash capacitor. Sears refused to give me a refund." "I accidentally made chloramine gas and experienced short-term breathing difficulties." "Yeah, well, I shorted out a nuclear submarine battery." silence
  - jacquesm 11y ago
    No, he did not short out the reactor, he shorted out the battery.
    - CamperBob2 11y ago
      Edited just before you posted that comment, because I somehow knew it was coming. Sigh.
brandmeyer 11y ago
That 450VDC electrolytic capacitor wasn't the worst failure I've experienced with such a device. I had one let go about 3 meters away from me. It sounded like a shotgun had gone off, and left my ears ringing for a few minutes. There wasn't anything left but the terminals.
- HankB99 11y ago
  Reminds me of a similar situation. We were working on a device powered by what looked like a 6 pack of 16 Oz cans caps charged to 500V. SCRs controlled the discharge of the capacitors into the device and caps were charged in opposite polarity so that the device could deliver current in opposite polarity depending on which way the mechanism was to move. There was a flaw in the logic that controlled the SCRs and in some circumstances both directions were on resulting in a direct short between the two banks of caps, discharging all stored energy in a fraction of a second (about 300 ms IIRC) That resulted in catastrophic failure of the SCR which propelled pieces of casing across the room and left my ears ringing. I asked that a cardboard box blast shield be placed over the H/W before participating in further tests.
rdtsc 11y ago
> This released profuse magic smoke and severely damaged the power supply. Magic smoke needs a magic fume hood or being outside ;-) I can't say for sure, but I would err guessing a lot of smoke coming out of exploding or burning electronic components is not good for you.
geerlingguy 11y ago
Early on in my 'take things apart for fun' youth, I knew that capacitors held a charge long after power was removed. So when disassembling a camera with built in flash, I popped off the small board holding the 330V capacitor and thought it would be a great idea to discharge it using the end of my needle nose pliers—for the tiny capacitors I'd done this to before, it might've caused a tiny spark, but nothing more. Well, I learned a valuable lesson that day; even relatively harmless camera flash capacitors can pack quite a charge days after a battery's been removed! The giant spark made me jump back and fall over my chair, and my pliers still have two nice molten burn marks where it touched the contacts. I'm just glad the pliers had rubber handles! I'm much more cautious around capacitors these days.
- blantonl 11y ago
  I did the exact same thing - took apart a camera and noticed the flash capacitor had a shock warning writing right on it, so I thought to myself "I better discharge this before it shocks me." I figured shorting it out using a screwdriver across the terminals would do the trick. A huge flash arc mini-explosion blasted that screwdriver and left me seeing spots for a few hours.
  - tajen 11y ago
    Smaller electricity lesson. We were studying noise on resistor-capacitor circuits at uni (waveform), with an oscilloscope. Teacher says to the most "experimental" student of the class: "You know, even 220V has noise at the top of the curve". The second the teacher turns his back the student put the probes in the power point.
    - mschuster91 11y ago
      What happened? Did the scope have over-voltage protection or was it fried?
      - jacquesm 11y ago
        It should have survived, depending on the probe in use and the input circuitry of the scope. But most quality scopes would just display a sine wave after you scaled down the Y axis a bit. Mine certainly would (elderly Tek).
AnimalMuppet 11y ago
> Think twice before "stop, drop, and roll" as the floor may be on fire Wow. Just... wow.
fidget 11y ago
Takeaways: Don't store strong chemicals in your bedroom Some of these seem the wrong side of irresponsible
Animats 11y ago
Darwin award applicant. "I had made some gunpowder and had some sitting on an outside table. I was experimenting with fuse design and was burning a fuse 6 feet or so away." "I bought some H2SO4 and used most of it immediately. Unfortunately the original plastic bottle didn't fit in my cabinet. So I transferred the contents to a couple of small plastic bottles. Finally, the cabinet was temporarily blocked so I decided to temporarily store them on a shelf next to my bed." "I had a few hundred mL of acetone and H2SO4 waste stored in a glass peanut butter jar."
- CamperBob2 11y ago
  Yeah, I enjoy occasional shenanigans with dangerous items and substances as much as the next nerd, but this guy is just plain reckless. He needs to find something else to do, preferably before something tragic occurs. He's incredibly bright (the X-ray machine with the 2D positioner is just plain brilliant) but he just doesn't seem to think far enough ahead.
- FatalLogic 11y ago
  Some of these incidents seem to have occurred when he was a child
jtchang 11y ago
How is this dude not dead yet?!
- tajen 11y ago
  This dude is really passionate. I don't know anyone who did chemistry for fun, let alone had any budget and enough parent leniency to do it before 18yo. As he grows up you notice he talks more and more about security gear. I don't know how someone can get into chemistry before 18. I understand reactions that are presented to me, but how do you get the initiative of trying something new? How can I be confident those are the only reactions that happen? OP has only produced H2S by mistake a few times in his life, far fewer than I'd expect anyone experimenting to produce unexpected chemicals.
  - JabavuAdams 11y ago
    > I understand reactions that are presented to me, but how do you get the initiative of trying something new? This is what kids do naturally, before they know any better. A lot of kids experiment with chemistry. The trick is keeping them alive and unmangled until they develop a respect for what they're working with.
    - brandmeyer 11y ago
      In my attempt not to drill my young kids' exploration out of them, I tell them that "X is a tool, not a toy!", for values of X like knives, fire, light sockets, etc. And then promptly talk about how to use them :)
mschuster91 11y ago
In school we had a public display exhibition - a series of LEDs mounted on PCBs with shifters. Like, you put in a color at the first PCB and pressed the "shift" button and the color would shift through the chain, the color of the last PCB in the chain would vanish. Each PCB had a capacitor on the 12V supply rail. So, I needed to swap the PSU because we planned to add more of them, and I plugged it out - and cut the supply cable with a scissor. Twelve capacitors blew out (I believe because the ICs turned off the power of the LEDs before the caps were discharged, they were ridiculously huge anyways)... right in the middle of school day, and a week before there was some retard running amok and killing students. tl; dr: Shorted 12 caps, huge explosion sound, peoples panicked and thought of a school shooting.

145 points by epsylon 11y ago

I'm almost glad I didn't pay more attention in chemistry class because I'm sure I'd do some of these blunders.

David 11y ago

In chemistry class in middle and high school, I thought all the safety precautions we took were stupid, given that we were using harmless chemicals to do harmless experiments. I wish this had been around, and it had been required reading--I would have all about that safety gear.

JabavuAdams 11y ago

Fantastic! I love reading accident reports, for some reason. There's so much practical knowledge contained in them.

brandmeyer 11y ago

Once upon a time, in the nuclear submarine navy, my shipmate tags out the ship's battery breaker. As part of the tagout, he checks that the ship's DC bus is deenergized - within the battery breaker box itself. During the check, he finds some voltage, which isn't entirely unexpected, since there is enough capacitance on the DC bus to hold it charged for a while. So he uses a specialized grounding probe - about 1/8" diameter copper rod with a reinforced handle - to discharge it. Unfortunately, he has misunderstood what was inside the breaker box and is actually shorting out the ship's main battery! This is a couple hundred volts DC, and a few thousand amp-hours of capacity, and it delivers enough current to instantly vaporized the grounding rod. He's knocked on his ass by the arc blast. Fortunately, he was correctly considering the box to be energized gear and was wearing a full set of PPE, suffering only minor flash damage to his eyes.

jacquesm 11y ago
Lucky guy, lucky too he used a relatively thin rod, a thicker one and it would have been quite a different ending. I did a similarly stupid thing one day. While repairing a clock for a display on a trade show I hooked the ground crocodile clamp of my scope to what I thought was the ground but which in fact was V- of the DC supply voltage of the neon light installation that was use to drive the display. I had a blind spot in the middle of my eyes for many days after that (and took out a fairly large chunk of the mains supply for the Eastern district of Amsterdam). The crocodile clamp totally disappeared, the scope, miraculously survived and wasn't even out of spec. Every time I use a crocodile clamp to hook it on to something I think back to that moment when the clamp makes contact and some part of me expects it to happen again.
- brandmeyer 11y ago
  > I hooked the ground crocodile clamp of my scope to what I thought was the ground but which in fact was V- of the DC supply voltage of the neon light installation that was use to drive the display. Yeao! I own a couple of high-voltage differential probes for this very purpose. Even though most single-ended scope probes are rated to 300V Cat II, I won't go anywhere near main's power with them.
CamperBob2 11y ago
Pretty hard to top that. "I bought some fuming nitric acid on eBay and spilled it on the carpet. Dad was pissed." "I fused two screwdrivers together with a photoflash capacitor. Sears refused to give me a refund." "I accidentally made chloramine gas and experienced short-term breathing difficulties." "Yeah, well, I shorted out a nuclear submarine battery." silence
- jacquesm 11y ago
  No, he did not short out the reactor, he shorted out the battery.
  - CamperBob2 11y ago
    Edited just before you posted that comment, because I somehow knew it was coming. Sigh.

brandmeyer 11y ago

That 450VDC electrolytic capacitor wasn't the worst failure I've experienced with such a device. I had one let go about 3 meters away from me. It sounded like a shotgun had gone off, and left my ears ringing for a few minutes. There wasn't anything left but the terminals.

HankB99 11y ago
Reminds me of a similar situation. We were working on a device powered by what looked like a 6 pack of 16 Oz cans caps charged to 500V. SCRs controlled the discharge of the capacitors into the device and caps were charged in opposite polarity so that the device could deliver current in opposite polarity depending on which way the mechanism was to move. There was a flaw in the logic that controlled the SCRs and in some circumstances both directions were on resulting in a direct short between the two banks of caps, discharging all stored energy in a fraction of a second (about 300 ms IIRC) That resulted in catastrophic failure of the SCR which propelled pieces of casing across the room and left my ears ringing. I asked that a cardboard box blast shield be placed over the H/W before participating in further tests.

rdtsc 11y ago

> This released profuse magic smoke and severely damaged the power supply. Magic smoke needs a magic fume hood or being outside ;-) I can't say for sure, but I would err guessing a lot of smoke coming out of exploding or burning electronic components is not good for you.

geerlingguy 11y ago

Early on in my 'take things apart for fun' youth, I knew that capacitors held a charge long after power was removed. So when disassembling a camera with built in flash, I popped off the small board holding the 330V capacitor and thought it would be a great idea to discharge it using the end of my needle nose pliers—for the tiny capacitors I'd done this to before, it might've caused a tiny spark, but nothing more. Well, I learned a valuable lesson that day; even relatively harmless camera flash capacitors can pack quite a charge days after a battery's been removed! The giant spark made me jump back and fall over my chair, and my pliers still have two nice molten burn marks where it touched the contacts. I'm just glad the pliers had rubber handles! I'm much more cautious around capacitors these days.

blantonl 11y ago
I did the exact same thing - took apart a camera and noticed the flash capacitor had a shock warning writing right on it, so I thought to myself "I better discharge this before it shocks me." I figured shorting it out using a screwdriver across the terminals would do the trick. A huge flash arc mini-explosion blasted that screwdriver and left me seeing spots for a few hours.
- tajen 11y ago
  Smaller electricity lesson. We were studying noise on resistor-capacitor circuits at uni (waveform), with an oscilloscope. Teacher says to the most "experimental" student of the class: "You know, even 220V has noise at the top of the curve". The second the teacher turns his back the student put the probes in the power point.
  - mschuster91 11y ago
    What happened? Did the scope have over-voltage protection or was it fried?
    - jacquesm 11y ago
      It should have survived, depending on the probe in use and the input circuitry of the scope. But most quality scopes would just display a sine wave after you scaled down the Y axis a bit. Mine certainly would (elderly Tek).

AnimalMuppet 11y ago

> Think twice before "stop, drop, and roll" as the floor may be on fire Wow. Just... wow.

fidget 11y ago

Takeaways: Don't store strong chemicals in your bedroom Some of these seem the wrong side of irresponsible

Animats 11y ago

Darwin award applicant. "I had made some gunpowder and had some sitting on an outside table. I was experimenting with fuse design and was burning a fuse 6 feet or so away." "I bought some H2SO4 and used most of it immediately. Unfortunately the original plastic bottle didn't fit in my cabinet. So I transferred the contents to a couple of small plastic bottles. Finally, the cabinet was temporarily blocked so I decided to temporarily store them on a shelf next to my bed." "I had a few hundred mL of acetone and H2SO4 waste stored in a glass peanut butter jar."

CamperBob2 11y ago
Yeah, I enjoy occasional shenanigans with dangerous items and substances as much as the next nerd, but this guy is just plain reckless. He needs to find something else to do, preferably before something tragic occurs. He's incredibly bright (the X-ray machine with the 2D positioner is just plain brilliant) but he just doesn't seem to think far enough ahead.
FatalLogic 11y ago
Some of these incidents seem to have occurred when he was a child

jtchang 11y ago

How is this dude not dead yet?!

tajen 11y ago
This dude is really passionate. I don't know anyone who did chemistry for fun, let alone had any budget and enough parent leniency to do it before 18yo. As he grows up you notice he talks more and more about security gear. I don't know how someone can get into chemistry before 18. I understand reactions that are presented to me, but how do you get the initiative of trying something new? How can I be confident those are the only reactions that happen? OP has only produced H2S by mistake a few times in his life, far fewer than I'd expect anyone experimenting to produce unexpected chemicals.
- JabavuAdams 11y ago
  > I understand reactions that are presented to me, but how do you get the initiative of trying something new? This is what kids do naturally, before they know any better. A lot of kids experiment with chemistry. The trick is keeping them alive and unmangled until they develop a respect for what they're working with.
  - brandmeyer 11y ago
    In my attempt not to drill my young kids' exploration out of them, I tell them that "X is a tool, not a toy!", for values of X like knives, fire, light sockets, etc. And then promptly talk about how to use them :)

mschuster91 11y ago

In school we had a public display exhibition - a series of LEDs mounted on PCBs with shifters. Like, you put in a color at the first PCB and pressed the "shift" button and the color would shift through the chain, the color of the last PCB in the chain would vanish. Each PCB had a capacitor on the 12V supply rail. So, I needed to swap the PSU because we planned to add more of them, and I plugged it out - and cut the supply cable with a scissor. Twelve capacitors blew out (I believe because the ICs turned off the power of the LEDs before the caps were discharged, they were ridiculously huge anyways)... right in the middle of school day, and a week before there was some retard running amok and killing students. tl; dr: Shorted 12 caps, huge explosion sound, peoples panicked and thought of a school shooting.