Things that terrify you on the bench.

[paulca]

No. 147:  The copper solder iron cleaning ball.

Why is it terrifying?  Well I have no holder for it. It floats around the desk, generally getting stuck to things and getting trailed around.  It's all very well until there is power on the bench too. 

Power + Copper wool ball = FIRE!

I have seen what you can do with a metal wool cleaning pad (Brillo pad in the UK) and a 9V battery, I really don't want to see what happens with a copper wool ball and a 30V breadboard circuit.

[fourtytwo42]

Put a leash on it (short peice of string) tied to something immovable to limit it's radius of action

I hate bangs, flashes and smoke in that order !!

[paulca]

I have a kennel for it on order.   It's leaving little solder dust poops everywhere too   I have to keep remembering to walk it so it can shake that stuff out on the floor where the hoover can get it.

[joeqsmith]

It's not what's on the bench that terrifies me, it's what is between the bench and the chair.  That's some terrifying stuff. 

[Cliff Matthews]

I hate spark shows. Why? My plywood-top bench is almost 16-ft long with ESD control via steel edge-strip grounded by a 1-meg resistor. When testing old amps (eg live chassis tube stuff), I need to look all the way down the bench for any metal equipment bypassing/grounding the strip. I plan to eliminate this by GFCI (RCD) and hard-wiring my fused 600w isolation transformer to separate power-bars at either end.

[paulca]

Putting my more serious face on....  I have kept it on the desk for the minimum after a quick safety check for "loose power".  It lives in the toolbox 99.9% of the time.

But I had it out today to fix a wiring mistake on a perfboard while I had two -+15V breadboards running and 12V PSU bannanas lying on the desk.

That inspired the post.  I think I deserve credit for realising and pointing out my little copper puppy is a death trap

[SeanB]

Quick cure for the ball of copper is to use a small tin can, either a tuna can, a tomato paste can ( bloody mary size) or even a small martini mixer can of soda with the lid removed. I just use a small 30g metal box with lid, because I have a box of them around, and stuck it to the soldering iron stand with some VHB tape. Copper ( actually brass0 scouring pad was the most expensive part, $1 at the supermarket for one big enough to cut into pieces to fill 4 cans.

[paulca]

By the way.. I said No. 147.  For me, No. 1 is ... a shorted high capacity, high discharge LiPo.

Than again I have yet to deal with mains.  Though I might be a bit more concerned about the LiPo... Number 2 would be a similar Lead acid.

[tautech]

Misplaced TH lead snippits !
DMM leads when adjusting CRO 3KV EHT voltages. 
Charged primary SMPS caps.

Not much else. 

Edit
Except radar........I was asked to fix one once, that thing did scare the shite out of me.

[M4trix]

The most thing that terrifies me on the bench is... dust ! Damn OCD... 

[Hextejas]

 

Me, I am the scariest thing. You should see what I do when I see smoke, which has happened 3 times in my short 4 month career.
I blow on it like its a birthday cake. No kidding. And then I reach in and start pulling wires.
Luckily, actually,  its by design, I never work with more than about 12v DC, which is usually what starts smoking as I get him shorted out.

[Cliff Matthews]

Me, I am the scariest thing. You should see what I do when I see smoke, which has happened 3 times in my short 4 month career.
I blow on it like its a birthday cake. No kidding. And then I reach in and start pulling wires.
Luckily, actually,  its by design, I never work with more than about 12v DC, which is usually what starts smoking as I get him shorted out.

Reminds me of something indelibly etched in youth. At 8-yrs I soldered something above my bed and a big blob of solder dropped on the sheets which started to smoulder. Yeah, blowing only ignites it..    It was a glass of juice close-by that stopped the hole from increasing past 4 inches in diameter. For sure my old man tanned my hide, but after half a century I can only recall few things are harder to put out than that.

[Adrian_Arg.]

It's not what's on the bench that terrifies me, it's what is between the bench and the chair.  That's some terrifying stuff.

if that terrifies me too, when my ds1054z sees me, it starts to sweat electrons 

[igendel]

Misplaced TH lead snippits !

I was just about to write that!

[GreyWoolfe]

Except radar........I was asked to fix one once, that thing did scare the shite out of me.

One of my teachers t ITT was a radar tech.  He worked on shipboard radar while live.  He also worked on the big phased array ground radar and said while testing, he watched a deer explode as it passed in front of the array.

[apelly]

Jewellery. Metal watch straps, bracelets, rings...

[BravoV]

My bottle of acetone, as I used it often and alot to clean stuff. So worry that one day I accidentally knock the bottle off by accident while its not properly closed yet, and pour it into hot solder ignites it ... and/or .. splashed and spilled all over the place on the bench table that has lots of "plastic" materials starting from oscilloscope, DMM, probes down to components. 

[EEVblog]

Simple 240V, I'm scared to death of it, seriously. I would never have made a sparky.

[vk6zgo]

Red back spiders?

[tautech]

Except radar........I was asked to fix one once, that thing did scare the shite out of me.

One of my teachers t ITT was a radar tech.  He worked on shipboard radar while live.  He also worked on the big phased array ground radar and said while testing, he watched a deer explode as it passed in front of the array.

That is scary !
I thought just the neon on a broom handle to check the small marine unit I fiddled with was going was bad enough but pre-cooked venison ? ? ? 

[stmdude]

For me, No. 1 is ... a shorted high capacity, high discharge LiPo.

I've done that, and it turned out to be pretty harmless (ignoring the hole in the wallet). The thin copper strips that goes out of each cell "simply" ceases to exist, and the short stops. It's quite a blinding flash, but it seems the strips acts as fuses when a couple of thousand amps go through them.

Now, anything but a dead short scares me. And AC.. 

[bd139]

Solvents scare me. I know someone who was sitting at their bench with an open can of cleaning fluid (I suspect this was IPA or something similar) and some of the vapor collected on the bench and went woosh due to an unknown ignition source. Everything on his bench was on fire, including him. But it was burning without a flame. You don't necessarily notice it immediately so you can't do much about it other than get the fuck out quickly. Most of his equipment was melted within seconds and he had partial thickness burns to his hands and face that took about a year to heal properly. His neck is scarred from this still and he can't fully extend his left hand due to the scarring on that.

Also after a little visit to Moorfields eye hospital, I wear some decent protective glasses while soldering. A tiny little blob of solder pinged off the sponge and went in my eye, fortunately towards the edge. If it had hit the middle, it would have wrecked my sight. You only get once chance there.

[Mr. Scram]

Solvents scare me. I know someone who was sitting at their bench with an open can of cleaning fluid (I suspect this was IPA or something similar) and some of the vapor collected on the bench and went woosh due to an unknown ignition source. Everything on his bench was on fire, including him. But it was burning without a flame. You don't necessarily notice it immediately so you can't do much about it other than get the fuck out quickly. Most of his equipment was melted within seconds and he had partial thickness burns to his hands and face that took about a year to heal properly. His neck is scarred from this still and he can't fully extend his left hand due to the scarring on that.

Also after a little visit to Moorfields eye hospital, I wear some decent protective glasses while soldering. A tiny little blob of solder pinged off the sponge and went in my eye, fortunately towards the edge. If it had hit the middle, it would have wrecked my sight. You only get once chance there.

Solvents also scare me when it comes to the more sneaky long term effects. Some of the household stuff is surpringly nasty.

[Rbastler]

Hydrochloric acid. I cleaned of some cat piss and shit with it, after my cat shat and pissed one my bench and into my "Allstrom" (able to be powered by a dc and ac grid) tube amp. The acid corroded everything nearby....

Guess my cat didn't like it, when I wasn't home for some days.....

Sent from my A0001 using Tapatalk

[paulca]

Thanks for the reminder about iso propanol burning with an invisible flame... and it being extremely flammable.

The stuff I bought has a safety encouragement anyway as the bottles as so unstable it's not wise to set them down while open anyway.

Unfortunately it also leaves a sticky residue.  This might just be the flux it dissolved spreading out or it might be cheap fake and not 99% pure as sold.

[bd139]

I find you have to wash with IPA then water then IPA then water again before the sticky goes away. It's annoying but it works.

As for safety encouragement, if you buy a bottle of it from RS, then they send it in a massive box with about 30 pages of hazardous chemical data!

Considering investing in an ultrasonic bath. You can get them for around £30 on Amazon.

[Mr. Scram]

I find you have to wash with IPA then water then IPA then water again before the sticky goes away. It's annoying but it works.

As for safety encouragement, if you buy a bottle of it from RS, then they send it in a massive box with about 30 pages of hazardous chemical data!

Considering investing in an ultrasonic bath. You can get them for around £30 on Amazon.

I think the general advice is to avoid the jewelry cleaner types. I've been eyeing ultrasonic cleaners for a while now too, but doing it right means spending some money.

[paulca]

As for safety encouragement, if you buy a bottle of it from RS, then they send it in a massive box with about 30 pages of hazardous chemical data!

Yep.  I got my flux pen in a box big enough to put a soccer ball in with a print out of the full 50 page safety datasheet and a HUGE hazardous materials sticker on the box.  The solder they sent in a much smaller envelope with it's 20 page safety datasheet.

[Mr. Scram]

That's the problem. If you do that with everything, it loses its punch. Of course, it's good to have the information nearby if something does go awry.

[mikerj]

Simple 240V, I'm scared to death of it, seriously. I would never have made a sparky.

Yep me too, and any HT circuits (e.g. working the back of an old CRT monitor/TV). My worrying tends to lead to sweaty palms as well, not really ideal

[paulca]

Simple 240V, I'm scared to death of it, seriously. I would never have made a sparky.

Yep me too, and any HT circuits (e.g. working the back of an old CRT monitor/TV). My worrying tends to lead to sweaty palms as well, not really ideal

I have been on the receiving end of the tube pull up caps on a CRT monitor.  Not something I want to repeat. Launched me clean across the room and left me as a shaking wreck in the corner, took an hour before I felt normal again.  But I'm still here and a little wiser.

[bd139]

Not sure if I'm higher impedance than the average person or not, but I've had a few zaps and don't find them particularly memorable. Couple of 240v ones made me say "fuck" followed by "mmmm bacon" and I discharged a CRT through myself once and didn't feel anything other than a ting on my toe where it came out.

[tautech]

Best one I ever got was from a valve PSU I built when I was ~13.....zap from the 700V plate terminals on a 5Z4.
45 years later I still remember bouncing off the bed on the other side of the room.
Had a zap or two from a Villiers engine I used to muck with but the 700V is always the one never forgotten.

The things we do  but that's how we learn.

[TheUnnamedNewbie]

Things I don't understand. Mains and tube amp get me thinking twice about every move I make, but if you know what you are dealing with, you also know how to do it safely. But if there is something on the bench and I don't know if it is isolated, or how it is wired up, or what voltages are present, that scares me. Where does the mains go? Are these huge-ass DC caps on the primary side of the DC/DC discharged on power-off?

That and Airsoft/RC batteries. These things don't come with current limit and the good big ones will happily deliver 250+ A on short... I've had to work on airsoft guns a few times and I always make sure to check for shorts 20 times, as well as powering it up with a lab supply (but not firing, since those guns can draw near 100 A peak, 40 A continuous) to check that there are no actives doing strange things.

[Johnboy]

One of my teachers t ITT was a radar tech.  He worked on shipboard radar while live.  He also worked on the big phased array ground radar and said while testing, he watched a deer explode as it passed in front of the array.

...and to think I was looking in the direction of my bench for potential terror. I think this "venison stew surprise" anecdote shocked me more than any of the things I have plugged in around here.

[bd139]

That's an old wives tale passed around. I worked on radar test rigs in a little metal room (stop RF getting in!) many years ago. Even at the business end of things on some massive phased array doodah, you'd get a little warm and that was about it. Most of the reasons for the wives tale existing came from the fact that humans, particularly ones carrying things, get in the way of the signals and don't give a crap about it. That is unless you tell them they're toast if they go near it.

The only time I've seen anything toasted properly was a pigeon became a short on the third rail on the tube in the UK with some loose ground strapping at Stratford. It just smoked a bit and it cleared. Smelled bloody awful.

[paulca]

I'm sure it's an "old engineers tale", but it is told that the microwave oven idea came from radar when they found perfectly cooked seagulls on the radar in Dover.

[Mr. Scram]

I'm sure it's an "old engineers tale", but it is told that the microwave oven idea came from radar when they found perfectly cooked seagulls on the radar in Dover.

The version I know of is engineers finding melted chocolate in their pockets. I'll admit, that version draws less attention than the seagulls.

[bd139]

When I put chocolate in my pocket it melts anyway.

[Mr. Scram]

Wikipedia at least agrees with the candy bar version. The seagull story seems to be an artistic embellishment.

"In 1945, the specific heating effect of a high-power microwave beam was accidentally discovered by Percy Spencer, an American self-taught engineer from Howland, Maine. Employed by Raytheon at the time, he noticed that microwaves from an active radar set he was working on started to melt a candy bar he had in his pocket. The first food deliberately cooked with Spencer's microwave was popcorn, and the second was an egg, which exploded in the face of one of the experimenters.[9][10] To verify his finding, Spencer created a high density electromagnetic field by feeding microwave power from a magnetron into a metal box from which it had no way to escape. When food was placed in the box with the microwave energy, the temperature of the food rose rapidly. On 8 October 1945, Raytheon filed a United States patent application for Spencer's microwave cooking process, and an oven that heated food using microwave energy from a magnetron was soon placed in a Boston restaurant for testing.[11]"

https://en.wikipedia.org/wiki/Microwave_oven#Discovery

[bd139]

Interesting. I worked for them once for a few weeks and had no idea about that 

[GreyWoolfe]

That's an old wives tale passed around. I worked on radar test rigs in a little metal room (stop RF getting in!) many years ago. Even at the business end of things on some massive phased array doodah, you'd get a little warm and that was about it. Most of the reasons for the wives tale existing came from the fact that humans, particularly ones carrying things, get in the way of the signals and don't give a crap about it. That is unless you tell them they're toast if they go near it.

The only time I've seen anything toasted properly was a pigeon became a short on the third rail on the tube in the UK with some loose ground strapping at Stratford. It just smoked a bit and it cleared. Smelled bloody awful.

Not sure why he would tell a tale like that.  He also said that the grass was dead for hundreds of feet in front and the ground was littered with the corpses and bones of animals.  The other thing he said that when working on shipboard radar live, as the antenna rotated, you could hear a hum from the superstructure as the antenna passed it.  I would like to think it wasn't all 

[Mr. Scram]

When I put chocolate in my pocket it melts anyway.

Apparently it was a peanut cluster bar, which melts at a higher temperature and of which Spencer was a fan. If he liked pure chocolate, we may not have had a disappointing way of reheating sad leftovers.

[paulca]

Not sure why he would tell a tale like that.  He also said that the grass was dead for hundreds of feet in front and the ground was littered with the corpses and bones of animals.  The other thing he said that when working on shipboard radar live, as the antenna rotated, you could hear a hum from the superstructure as the antenna passed it.  I would like to think it wasn't all 

I know that when I try and use my phone outside of work, which is about 1000 yards from the Belfast City airport radar it cuts out with the same regularity that the radar rotates.  If I walk around the other side of the building it's fine.  I expect anything that breaks the line of sight to the radar would help.

[Mr. Scram]

Not sure why he would tell a tale like that.  He also said that the grass was dead for hundreds of feet in front and the ground was littered with the corpses and bones of animals.  The other thing he said that when working on shipboard radar live, as the antenna rotated, you could hear a hum from the superstructure as the antenna passed it.  I would like to think it wasn't all 

I don't know why someone would tell spectacular stories about death rays and violence, which also happen to be nearly impossible to verify. 

[BrianHG]

This 10k$ Mitsubishi AM3501R 35 inch multiscan computer monitor.  After paying half price for it used at the time, I had to service it.  And a few mods, after stretching it's horizontal scan rate to 45Khz and RGB drive amp change, and refocusing a few times, I once got the shock of my life from it when my hand slipped doing a live adjustment in the back.

Even the powerup cycle, that 450watt switching would wine up like a rapid electric camera flash charging, but much deeper and louder scared a few of my friends until you got used to it.
However, being the only one at home with a 1024x768 (after mods) progressive scan 35 inch screen with perfect RGB convergence from corner to corner in 1994, with a home made de-intelacer for TV & DVDs lateron the PC in progressive scan as well, you couldn't get better picture at the time.

[bd139]

Not sure why he would tell a tale like that.  He also said that the grass was dead for hundreds of feet in front and the ground was littered with the corpses and bones of animals.  The other thing he said that when working on shipboard radar live, as the antenna rotated, you could hear a hum from the superstructure as the antenna passed it.  I would like to think it wasn't all 

That's probably from the oodles of poisoned pellets they scatter around to stop them shitting on the building and aperture.

[Neilm]

When I put chocolate in my pocket it melts anyway.

When I put chocolate in my pocket, it disappears (my excuse)

[Johnboy]

I've been studying for the GMDSS Maintainer license and the horror story which Grey Woolfe related frankly dovetails with the effusive, repeated safety warnings about even repairing slotted arrays and so on. While I don't feel particularly comfortable working with RADAR systems anyway, I have to wonder what legitimate damage microwave energy is genuinely capable of doing on a grand scale-- my gut says that the technology has been thoroughly tested for more applications than mere echolocation.

[bd139]

It usually causes non penetrating surface burns. Look for Active Denial System on YouTube etc.

[rrinker]

 My soldering station came with a stand that incorporates a place to put the copper ball, so mien goes nowhere. Still the best tip cleaning thing, beats a wet sponge any day.

 What truly scares me is high voltage. I'm glad US mains is only 120V, but even then - I NEVER work on anything without shutting off the breaker first. I'll let the pros be crazy and change out a wall switch without killing the branch circuit first. But what I really mean is tube voltage. It all stems from an incident when I was a kid, a neighbor down the street knew I was into electronics so when he moved away he gave me this huge box full of parts and a few complete items, including two tube radios, one AM/FM and one AM only. Plus this other circuit I never could figure out what it did. There were a few switches and potentiometers, and some large transformers. Just one pair of output terminals, and a lien plug. With my extremely limited test equipment, I couldn't figure out what it did. I forget what the output measured, but none of the controls made a noticeable difference other than what was obviously the main on/off switch. I no longer have this piece, but I suspect it was some sort of frequency generator.
 Anyway, the AM/FM radio was 100% complete and worked. The AM radio, the tuning knob was broken off. So I had it powered up and was using a screwdriver to turn the tuning capacitor. Holding it by the well-insulated handle. All was going well until my hand slipped off the handle of the screwdriver onto the shaft. Add that I was working in the basement, standing on the bare cement floor. I now had 400+V going through me. I couldn't move, it was paralyzing me. I could see, and hear - just a few feet away, outside on the patio, my Mom and some neighbors were talking, but I couldn't yell for help.  Only after a bit, I started shaking enough that I finally broke contact with the tuning capacitor and was able to move. It seemed like I was stuck there for an hour, it probably was seconds. The only good thing is it was my right hand, so the current was flowing nowhere near my heart. Ever since then - I am deathly afraid of working around high voltage equipment. Even jumpy when discharging the anode circuit on a CRT. And even after grounding it 3 times and triple checking that nothing is plugged in, I'm still jumpy if a wire brushes against me even though I know beyond a doubt that all capacitors are discharged.
 I learned the hard way about 120V AC. "Don't stick your fingers in a light socket" "why?" My grandmother had a floor lamp that for some reason had no bulb in it. Stuck my fingers in the socket - nothing. So I turned the switch on the side of the socket and tried again. Oh, that's why. I was probably 2 or 3.

[jgalak]

As for safety encouragement, if you buy a bottle of it from RS, then they send it in a massive box with about 30 pages of hazardous chemical data!

Yep.  I got my flux pen in a box big enough to put a soccer ball in with a print out of the full 50 page safety datasheet and a HUGE hazardous materials sticker on the box.  The solder they sent in a much smaller envelope with it's 20 page safety datasheet.

Heh.  I got a box from Digi-Key the other day, complete with dire warnings of "freight aircraft only" and "primary lithium batteries inside".  Giant box, tons of padding.  Inside (among other components), were the 3 CR2024 batteries I had ordered....

[Bear207]

...
 I learned the hard way about 120V AC. "Don't stick your fingers in a light socket" "why?" My grandmother had a floor lamp that for some reason had no bulb in it. Stuck my fingers in the socket - nothing. So I turned the switch on the side of the socket and tried again. Oh, that's why. I was probably 2 or 3.

I share the exact same learning experience - except believe I required more than one lesson in those earlier years. 
An electrician moonlighted for my parents oil burner service company.  He "taught" me all sorts of great things about electricity when I was far too young to appreciate the potentially deadly outcome....and my mom never was the wiser or the world would have been without one said electrician.  Nonetheless I built my first alarm system to track my parents movement in our large house using 120VAC and hand made switches in the floorboards / stair treads.  The house never burnt down and I removed all that wiring before I left for college.  My father knew all about it and got a kick out of it.  He also knew I was smoking at age eight....so he sure had a different parenting code than would be acceptable nowadays.

My fear is water, hate working with any sort of plumbing, always worried about leaks.  Electricity has my respect, not fear.  Shows you folks just how dangerous I might be aye?

Reference RADAR, I know a US Navy Seabee who was blinded for almost thirty days (with his entire company) when a RADAR installation was activated while they were inside the array in Alaska during WW II.  None of them suffered permanent physical damage, however, the emotional was another story.  Dennis did laugh when telling how all senior officers on that base were gone within twelve hours of the incident.

[Neomys Sapiens]

Not sure if I'm higher impedance than the average person or not, but I've had a few zaps and don't find them particularly memorable. Couple of 240v ones made me say "fuck" followed by "mmmm bacon" and I discharged a CRT through myself once and didn't feel anything other than a ting on my toe where it came out.

Regular AC doesn't scare me much anymore. The pump seems to take it and there will be something severely wrong when it doesn't anymore. Except one time. High summer, industrial building, thin wet soaked cotton overall. One leg, complete flank and buttocks and one arm in contact with structure. Other hand 'live'.
I felt shaken.
But the worst bite came from a fully charged professional photoflash unit (mains operated). Discharge to the heel of the hand. It bit. It stank. It took a long time to heal.

[paulca]

  I learned the hard way about 120V AC. "Don't stick your fingers in a light socket" "why?" My grandmother had a floor lamp that for some reason had no bulb in it. Stuck my fingers in the socket - nothing. So I turned the switch on the side of the socket and tried again. Oh, that's why. I was probably 2 or 3.

Pretty close to my first shock.  Took the bulb out and stuck my fingers in the light socket.  Then when nothing exciting happened I figured I'd turn it on and repeat.  Still nothing happened.  But at age 4 my inner engineer proposed that the pins in the light fitting needed to be pushed down, as they would be by the bulb.  FLASH, black residue up my fingers.  My parents, sleeping in the bed beside the lamp woke and went into near panic mode.  I wondered what all the fuss was about.  It hurt, but was just a quick jolt.

[IanMacdonald]

Changing large CRTs. Fortunately a thing of the past.

One time was swapping out a 42" job with the help of an apprentice when a guy came into the workshop and started an argument with him. Just had the thing off its mounts and in our hands, the worst possible time for this to happen. Guy who came in was so stupid he couldn't see the hazard he was causing, and if it had imploded he'd have been worst off as he had no face protection.

[katzohki]

I was once shocked with 4000 VDC, but I agree with Dave. That AC stuff can F right off

[Mr. Scram]

I think a crocodile on my bench would terrify me a bit. Not the clips, a proper hissy snap snap one.

[tggzzz]

...so he sure had a different parenting code than would be acceptable nowadays.

Not entirely, fortunately...

I taught my daughter about electricity with (a) a old Zerostat and (b) the back of her hand lightly touching an electric fence.

I sent her up in aircraft (alone) before she could start to drive a car.

We backpacked around India, not knowing where we were going to sleep the next night.

My brother made fireworks and the like with his grandson.

Both have survived and are great people.

[bd139]

Sounds like a good and memorable childhood

You have to expose your children to risks, new and insane experiences regularly. It's the spice of life.

My nan gave me matches and newspaper and said go and make fires in the back garden. I burned her shed to the ground. That's parenting 

[Peeps]

When I was younger I blew a cap up inches from my face and it forever made me terrified of reversing the polarity on them. I ran panicked from my desk assuming I was covered in acid but stopped when I realized I was fine. 

Since then Ive had a few moments with rapidly discharging caps usually due to a slip of a probe and the flash and bang are always extremely jarring.

[sarel.wagner]

My Girlfriend on the bench..... That means I have done something bad , or I am soon going to 

[Fludo]

Big angry DC filter caps in power supplies, rotating shafts and baggy clothing, exposed conductors, my girlfriend nagging about how much of a mess it is.....

[jeremy]

I think you are all missing the most important one: when you knock a DIP40 off the bench, it lands pointy side up and you accidentally stand on it, hard. Fortunately surface mount has solved this problem...

[paulca]

and you accidentally stand on it, hard.

At least twice as you'll initially recoil in pain, but put your foot back down with it still attached.

[iaso]

Having been zapped by 240 volts on several occasions. I would say...240 volts,

Also, my cat when I'm soldering, she loves to jump on my bench, and as my bench is in a room without a door it's not always easy to ensure she doesn't bother me.

[Nitrousoxide]

Ironically it's not whats on the bench, but the lack of a said bench.

Hoesntly, working with a cramped desk and a large test jig is a nightmare. I think I've spent more time pulling probes back onto the table than attaching them to test points. 

[Cliff Matthews]

Yes been there with the flimsy bench (or none at all) but on flimsy projects, this one left me amazed as to how our beloved Mehdi-boom still lives..
https://youtu.be/lT3vGaOLWqE?t=456

[sixtimesseven]

Everything high power high voltage (kV's). If youre lucky you'll die on the spot.
If your unlucky you keep going. But the current will find the lowest resistance path trough your body which usually are your blood vessels - And burn them from the inside. You can live for days but unless the damage is contained to non essential parts of your body you will die from blood poisoning eventually.

Source: My sister just finished med school... Our family dinner stories now sooner or later always drift towards horrible ways to day 

[drussell]

Yes been there with the flimsy bench (or none at all) but on flimsy projects, this one left me amazed as to how our beloved Mehdi-boom still lives..

Uhh...  Because it is all staged BS? 

You can't see the video editing and effects?   

[Cliff Matthews]

Yes been there with the flimsy bench (or none at all) but on flimsy projects, this one left me amazed as to how our beloved Mehdi-boom still lives..

Uhh...  Because it is all staged BS? 

You can't see the video editing and effects?   

Well since I help identify "good candidates" for Electronics YouTube channels, I thought it was real and so did others on the forum..
https://www.eevblog.com/forum/chat/electroboom-sinking-to-new-low-in-safety-what-to-do/

[Neomys Sapiens]

I think a crocodile on my bench would terrify me a bit. Not the clips, a proper hissy snap snap one.

I think that would be mutual. Poor thing is not exactly well disposed for managing steep vertical gradients.

[paulca]

So, having started this thread about the copper wool ball....

"Frodo" has a new kennel:

[tggzzz]

So, having started this thread about the copper wool ball....

And back to the topic, one thing that frightens me is the shards of solder in such brass balls being spilled over the bench - and into whatever I'm working on.

[Quarlo Klobrigney]

I agree, the cat.
Especially when he tries to drill or grind Beryllium.
He is for the most part, isolated from the lab by a heavy duty screened door. He tends not to whine as much if he can see and hear what's going on. (From the other side that is.) To many things to kill all 9 lives in here.
Pictures soon.

[Cyberdragon]

I agree, the cat.
Especially when he tries to drill or grind Beryllium.
He is for the most part, isolated from the lab by a heavy duty screened door. He tends not to whine as much if he can see and hear what's going on. (From the other side that is.) To many things to kill all 9 lives in here.
Pictures soon.

Your cat can drill? We definately need a photo of that!

[radar_macgyver]

I suspect much of the legend around how dangerous radars are is a result of hazing/initiation rites among radar techs in the military. I haven't been around a radar that outputs more than a megawatt, but you still treat them with respect. That's probably what the hazing was intended to do. The one time I was exposed to high power RF, it felt like a sunlamp.

Stuff on my bench that I shy away from include chop saws and table saws. Quadcopters with carbon fiber blades can be quite dangerous indoors.

[JohnPen]

Back in the 60s the Royal Radar Establishment in Great Malvern UK had a very long range radar that used to switch off it's beam when pointing to towards the hills.  The hills were only about a mile away and it was believed that it could be a damaging to people walking there.   It was capable of tracking aircraft flying over the Nederlands etc.

[SeanB]

Aircraft RADAR array test box was a nice box lined with carbon foam waffle on the walls. Replace any of the foam and you had to burn it in first, which meant rolling it to the window, shoving the end outside and running the unit under test for about an hour till the smoke cleared and it was burnt in. The smell lingered for about 2 weeks though.  Magnetron test load on the bench was a section of rectangular waveguide around a quarter meter long, tapering in thickness from the flange to a weld at the end. Inside it was filled with a blend of ferrite powder and copper dust, with an epoxy added to keep the lot in place in the waveguide. Made a pretty efficient place to warm up pies, just put them on the top in the wrapping and foil, and leave for 5 minutes till piping hot. Paper of the pie would be brown and charred underneath from the heat, but the pies were fine as the foil base provided enough heat spreading.

Now we also used the test bench to check AWS systems, so doing that we had to make sure no flights were overhead, they did not like getting that lock on warning from testing using the actual missile seeker pattern.

Now, on my bench I have some bottles of ethanol 180 proof, some methanol 95% pure and some MEK solvent, all in glass bottles. Never use them directly but always fill a small dropper bottle with the solvent instead, so the amount on the bench is limited ,and it is easier to apply where needed.

[beenosam]

Hydrochloric acid. I cleaned of some cat piss and shit with it, after my cat shat and pissed one my bench and into my "Allstrom" (able to be powered by a dc and ac grid) tube amp. The acid corroded everything nearby....

Guess my cat didn't like it, when I wasn't home for some days.....

Sent from my A0001 using Tapatalk

I would not have a cat after that :-o

[paulca]

Hydrochloric acid. I cleaned of some cat piss and shit with it, after my cat shat and pissed one my bench and into my "Allstrom" (able to be powered by a dc and ac grid) tube amp. The acid corroded everything nearby....

Guess my cat didn't like it, when I wasn't home for some days.....

Sent from my A0001 using Tapatalk

I would not have a cat after that :-o

I think the cat is telling you something.  You have not lived up to it's standards.  Tut tut.  Though shalt be a good owner.  Your master cat demands it.

[chipss]

The tip cleaner cracked me up, just stuffed in a new one and got a new sponge, not have much left of the originals....sometimes it’s the small things 

[Tflynn6693]

Finding out I fed DC into my spectrum analyzer!

Tom

[peteb2]

For me it's opening up a piece of gear for repair that the owner says they've had a look-see at previously. It's not so common these days but i used to have some real nightmares where the owner said they'd tightened up; "all the loose screws", meaning every pot or trim capacitor was way off and the circuitry way out of any alignment. Faulty equipment that was now also a mile out of alignment was often a recipe for disaster meaning hours of work while there was all too often no money in bothering to pursue fixing the thing because the owner wouldn't want to pay....

[Teledog]

Unstable glasses of liquor (ie: wine or those feakishly tall beer glasses)..with bits of scrap underneath..making the glass even more unstable.
But hey, if Big Clive can do it..there may be hope for all! 

[Mr. Scram]

Unstable glasses of liquor (ie: wine or those feakishly tall beer glasses)..with bits of scrap underneath..making the glass even more unstable.
But hey, if Big Clive can do it..there may be hope for all! 

Solution: remove liquor.

[jgalak]

Unstable glasses of liquor (ie: wine or those feakishly tall beer glasses)..with bits of scrap underneath..making the glass even more unstable.
But hey, if Big Clive can do it..there may be hope for all! 

Solution: remove liquor.

Better solution: drink the liquor.   

[Calambres]

I've had my share of mains jolts over the years: waaaay back when the usual mains voltage here was 125V, then 220V, then 230V and now 240V. I've tasted them all 
I'm glad I've never had 380V three phase mains! 

I usually deal with valve guitar amplifiers and although I've never been bitten I must confess it scares the hell out of me: I always (try to) follow the "one hand in the pocket" golden rule.

I once knew an electrician who didn't bother to use a meter or other kind of probes to detect mains voltage; he grasped both terminals and felt whether there was current or not, and without even raising an eyebrow... is it possible to get used to mains voltage? 

[paulca]

I once knew an electrician who didn't bother to use a meter or other kind of probes to detect mains voltage; he grasped both terminals and felt whether there was current or not, and without even raising an eyebrow... is it possible to get used to mains voltage? 

That sounds like you are volunteering to test   Remember to video the exercises

Kidding of course.

I got zapped last week by the plug pins of my laptop, AFTER it was unplugged.  I pulled the plug and my finger slipped under and touched the pins.  It is half insulated so you can't touch them while they are connected to the mains.  I expect I got zapped by the hot side filter caps.  It hurt, but not that much, however, unlike my previous zaps it continued to linger as a dull pain and my finger twitched randomly for an hour afterwards.