I took the end caps off of a dead F40T12 with the help of a heat gun. I was chipping the brown basing cement off of the ends with some flush cutters to prepare to take a picture of the electrodes (bad idea, I know). At this point I had the tube laying pretty much horizontal on the table.

I guess I got a little too aggressive with my flush cutters! The whole flare and electrode assembly on the end I was working on suddenly cracked off and was instantly sucked down the tube at very high speeds due to the vacuum. The high speed projectile flare assembly then collided with the other side of the tube, blowing it completely off and then continuing to fly until it hit a shelf a couple feet away. When I opened my eyes, there was a cloud of phosphor powder in the air around the far end of the tube and little glass bits absolutely everywhere.

I am very lucky that my brother was not standing there, and also pretty lucky that my brother was the only one who heard the loud WHOOSH-BANG that occurred. After the incident, I promptly opened a window for a bit. Then I cleaned up everything I could (only found one electrode assembly, not sure where the other one went). I cut the rough ends of the glass tubing off with a hot nichrome wire, and later I might wash the phosphor out as I hear mercury absorbs into it. It is obviously soda-lime glass, so IDK if I can do anything with it, but whatever. This whole thing could have been avoided if I had peacefully snapped the evacuation tube before messing around with it. Lesson learned.

Anyone else have any interesting stories of rapid lamp vacuum loss?

Another moron is breathing mercury vapor at his own will. Stop doing this stupid thing.... And next time you'll end up with glass in your eyes... Yes, breaking the tubulation is a way to do. Even make a small crack at the end of tubulation if possible with a small fire or hot wire and wait for a few hours for air to fill in. At least do it outside, older tubes can contain up to 100mg of mercury.

Don't wash out the powder without a disposal plan of the washing water.

The problem with that is that if you release it into nature, or into the municipal water treatment system, that the elemental mercury will be converted to various forms of methyl mercury by the bacteria found in the soil/sludge. And while elemental mercury's risks are somewhat manageable, (di)methyl mercury and other organic mercury compounds are just on a whole different plane of toxicity.

Think of it like this: elemental mercury is like getting stabbed with a carpet knife at a bar fight. Organic mercury compounds are like someone pulling out a flame thrower in said bar. Organic mercury compounds are inevitable everywhere where the bacteria are that convert mercury to organic mercury compounds.

Mercury is NOT typically filtered out by the municipal water treatment system!

Well, dangers to the environment from a *single* tube are certainly overhyped. Once diluted in the air or water, concentration will drop to practically background levels. Mercury has a high affinity to sulfur, so meeting a lot of hydrogen sulfide in the sewer, it will be be rapidly converted to insoluble and relatively non-reactive mercury sulfide. Still, breathing mercury-adsorbed powder from a broken tube is certainly not the best way to do. Mercury is not that toxic in the elemental form, and yes tuna fish we all like to eat may contain up to 1 mg/kg of much more dangerous methylmercury, but intentionally breaking fluorescents at home still not the best way to do

By the way, you can easily buy clean virgin glass tubes in soft glass or boro, should you play with glassblowing. Do not re-use fluorescent tube glass, as some idiots on Youtube do. Heating such glass will certainly evaporate adsorbed mercury, and that vapor will be right in your mouth through the blowing tube. Also, tube glass is thin wall, optimized for machine production, but inconvenient for hand glasswork.

 

Jup. Many neon shops also sell glass tube in various sizes, as well as fresh, non-contaminated phosphors if you want to do stuff with that.

At work we have a whole bunch of glass tube meant for scientific glass blowing. Good stuff, easy to work with. Scientific places also sell it but probably a bit more expensive.

Boro is nice but you need a lot more heat to work it. Soda lime can still be worked with a natural gas/air flame, propane/air preferred (propane burns hotter). For boro, you kinda want a gas/oxygen torch.

(I am aware a single tube broken doesn't do much harm, but you still don't want any contamination in your living space. If i (...) around with them, it's at work, in the laboratory fume hood).

@RRK
"at his own will" is an interesting way to say it . C'mon. And of course I did not break the tube with the intentions of using the tubing for glassworking, as I had no intentions to break it at all. If I really wanted glass tubing, I obviously would have just bought it. Amazon, Ebay, or of course a dedicated glass supplier. And I would certainly buy borosilicate so I can actually do something with it without a whole darn annealing oven. Now I know not to mess around with fluorescent tubes. Whatever.

@Laurens
Disposal of the washing water (if I choose to wash it, which I probably won't) would be by evaporation outside. Of course this counts as releasing into the environment, but the mercury has to go somewhere. I did a similar thing with a broken CRT to get the phosphor. Just evaporated the water and was left with phosphor powder. IDK what I'm gonna do with it but whatever. Of course keeping contaminated phosphor in a bottle inside might not be the best idea, but better than leaving it coated with wide surface area on the inside of a tube open to the inside air.

Neon sign shops?! I never bothered even researching if there were any around here because I figured they certainly no longer exist. I wouldn't want phosphored tubing for my proposed purposes anyway.