Anyone have a light bulb blow up?

[Greg Bernhardt]

Was shaving just now and one of my mirror wall light bulbs blew up. Luckily it's encased in the light fixture with an opening at the top so it was contained a bit, but some glass blew up through the top and rained on me. The glass was very hot, so I'm guess it wasn't LED.

 

[phinds]

Yeah, I had it happen once with a 100Watt incandescent. Never did figure out just what was going on but I've always assumed a short circuit, somehow, inside the bulb base or the housing. I didn't do anything to the housing and new bulb worked fine so I guess it was the bulb. MAYBE it was an overly energetic filament burnout. Usually they just sort of go "pop" with a minor flash, but ...

 

[anorlunda]

Wow, that sounds pretty rare that you were standing right there when it blew. Good thing you were not hurt.

There have always been problems with light fixtures that do not provide enough cooling for incandescent bulbs. That is why they come with a maximum wattage rating. But even that wattage rating depends on installation conditions that might not be met.

Looking at the remnants of the bulb it should be easy to verify that it was incandescent. Let us know.

If there is a PCB or multiple components it is LED. But LED bulbs run much cooler so that making them actually blow the glass from overheating is harder to achieve. I suppose it might be possible to have a short circuit internal to an LED bulb.

 

[dlgoff]

Was shaving just now ..

Perhaps a drop of shaving cream landing on the bulb?

 

[Baluncore]

Quartz halogen globes can explode. That usually happens after the surface is contaminated so there is a huge differential thermal expansion. Maybe an invertebrate moved into the fitting and contaminated the surface.
If you are too close to the explosion, you will hear only a click as there will be a local shock wave, but that wave should normally be contained by the fitting.

 

[berkeman]

Perhaps one failure mode would be if the low pressure glass bulb (with inert gas inside) failed abruptly, which could cause a small implosion with the resulting noise and expulsion of glass shards. That would also probably burn out the filament pretty quickly, if it weren't torn by the implosion.

Greg -- can you post a few pictures of what's left of the bulb and glass pieces?

https://en.wikipedia.org/wiki/Incandescent_light_bulb

 

[anorlunda]

I like @Baluncore 's idea about a drop of cold water on a hot bulb.

 

[symbolipoint]

To the title question: YES. About four years ago.

New, cheap, incandescent bulb at the ceiling between a glass-frosted shade and the ceiling; POP! a piece of the bulb glass flew out and another also flew out with it; one of the pieces was caught on the glass-frosted shade and another piece was on the floor.

My advice is do not buy cheap light bulbs.

 

[darth boozer]

I have had several 100W incandescent bulbs blow with a loud bang and the intact glass bulb flying down onto the carpet while the metal bayonet-type base remained in the ceiling fitting. The wires connecting the bulb to its base were vaporized, but the fuse was intact.

 

[essenmein]

The wires connecting the bulb to its base were vaporized, but the fuse was intact.

That's how they work, the circuit blows to protect the fuse.

 

[russ_watters]

Was shaving just now and one of my mirror wall light bulbs blew up. Luckily it's encased in the light fixture with an opening at the top so it was contained a bit, but some glass blew up through the top and rained on me. The glass was very hot, so I'm guess it wasn't LED.

Wow, that's...terrifying.

I once touched a bulb to replace (flickering, not dead yet) it after having just washed my hands and it blew up probably due to thermal shock from my wet fingers. Any chance some condensation dripped on it?

 

[Vanadium 50]

I've had a bulb come crashing down when the fixture cracked (thermal shock, presumably) and I've had a halogen pop. That was a torchiere-style light so it was contained. I assume the bulb got some dirt on it in a bad place at some time.

 

[eq1]

I had no idea this was even possible but it looks like Google did.

https://www.pacificlamp.com/what-makes-a-light-bulb-explode.asp

 

[sophiecentaur]

The wires connecting the bulb to its base were vaporized, but the fuse was intact.

We once lived in a very 'under-fused' house and it was fairly common for a filament lamp to blow and take out a breaker. Now that implies more current was passing for a while. I wondered how an evaporating filament, which would be getting thinner and thinner, yet dissipate more Power. The surface area of the filament also decreases so it would run hotter (and increase the resistance further) so is there a vapour phase which forms a (low R) arc? That seemed the only conclusion.

 

[Guineafowl]

We once lived in a very 'under-fused' house and it was fairly common for a filament lamp to blow and take out a breaker. Now that implies more current was passing for a while. I wondered how an evaporating filament, which would be getting thinner and thinner, yet dissipate more Power. The surface area of the filament also decreases so it would run hotter (and increase the resistance further) so is there a vapour phase which forms a (low R) arc? That seemed the only conclusion.

I always thought that the break in the filament grows, briefly drawing an arc between the stouter support wires. The arc, being lower impedance, supports more current flow.

 

[hutchphd]

Sometimes the electrodes are close together relative to filament length. Also aren't the filament also coiled to increase resistance? Both would promulgate the ionization cascade.
As a technologist for LEDs I have a pointed question for @Greg Bernhardt ...Who still uses filament bulbs ?? I must admit I hoarded 100W filament bulbs when the alternative was CFL...they were horrible. Join the non-Edisons !

 

[sophiecentaur]

.Who still uses filament bulbs ??

I know they are on the way out and I don't think I use any - apart from some Haolgen spots. The various attempts to produce a black body spectrum in an alternative way have arrived at some very decent LED sources but I haven't seen a LED~ source that behaves itself appropriately like a filament when dimmed. Mixing RGB light sources doesn't necessarily model a dimmed filament without some clever synthesis. The dimmed LEDs in your new uplighter really don't do the trick when you want Midnight Lighting.

CFLs just make me feel sick.

 

[trurle]

Sometimes the electrodes are close together relative to filament length.

Yes, it is the case i observed once. The failure started from glass crack at base, then in few seconds inside the bulb the whirls or white smoke of tungsten oxide developed, and finally an arc shone between leads, far from filament.

 

[dlgoff]

I hoarded 100W filament bulbs when the alternative was CFL...they were horrible.

There ARE some that seem to have very short lifetimes. If you can still find them, filament bulbs that are rated for 130 VAC (usually found printed/molded in the metal base along with the bulbs wattage) will have a fairly long lifetime. The cheep ones usually indicate 115 or 120 VAC.

 

[artis]

never have I seen a filament bulb explode from filament burnout , they typically either just make a bright flash and either blow a fuse. although I cannot rule it out
What I have had is a bulb explode when under thermal stress, like a cold water drop being dropped on the surface of the hot glass, I think some posters already said that here.
Glass seems to be the least structurally capable material when it comes to temperature differences , especially sudden ones.

Although this would be speculation I think a drop of some cold liquid even if very small would be more than enough to blow the bulb once hot.
some would say how does it then survives an outdoor environment with say a fog or a mist, but I think it only does that because the mist or fog increases very gradually and is rather homogeneous with fine aerosol particles spread out evenly so the cooling of the bulb surface is even.

 

[Tom.G]

Some incandescent lamps are rated for outdoor use, presumably a different glass to withstand thermal shock. Outdoor rated floodlights are/were rather common. There are also the "appliance" rated lamps as used in home refrigerators.

Cheers,
Tom

 

[sophiecentaur]

a different glass to withstand thermal shock

A double skin envelope could be used? or just thick glass. Not as 'efficient' perhaps but no option if it avoids getting out the cherry picker to replace a bulb.

 

[wukunlin]

There was a ceiling lamp in my parents house and it used one of those 300w halogen bulbs. It exploded and showered tiny pieces of glowing (from the heat) glass over the living room.

 

[BillTre]

I have had filament bulbs blow up, but not recently.

I like the idea of moisture or some other material thermally stressing the glass, leading to failure.

However, contrary examples:

When I was a kid, our house had two vertically aligned bathrooms, one of which had a leak from a "pan" under the shower stall and the water seeped down to the downstairs bathroom and ended up flooding the light fixture. The light fixture was a globe type hanging from the ceiling. It was 1/3 to 1/2 full of water. The light was still working. I turned the light off, took off the fixture and the bulb was about 1/3 full of water inside of it! The bulb was mounted with the electrical socket pointing up. Could not figure that one out.
Drain the fixture, put in a new bulb and everything worked.
Parents got the shower stall fixed.

This is also somewhat reminiscent of some aquarium light fixtures I made when I was a kid. These involved having immersed aquarium bulbs (long cylindrical shaped, with electrical connections (socket) about 2" above the waterline). This was supposed to make for more efficient light transmission into the water as well as extending the bulbs life (kept cooler). This was in the 1960's when aquarium lights were very underpowered (compared to today). I would not recommend this method for others, but it did work without problem for me.

Also relevant were cases when a lit aquarium light fixture would occasionally fall into a tank. Sometimes the bulbs would blow up, sometimes not, sometimes the lights would continue going until I unplugged the light.

Perhaps these aquarium lights were made with more resistant glass. It would not be uncommon for these lights to get lots of small drops and splashes on them. Some, but not all, were plastic coated.

 

[symbolipoint]

I like the idea of moisture or some other material thermally stressing the glass, leading to failure.

You LIKE this?

 

[BillTre]

You LIKE this?

As an explanation of the observed event.
Not as an ongoing event in peoples homes.

 

[fluidistic]

When I was a child I used to play with a syringe while taking baths. Water in, water out. I once hit the light bulb and sure enough it exploded all over the place.

 

[artis]

When I was a child I used to play with a syringe while taking baths. Water in, water out. I once hit the light bulb and sure enough it exploded all over the place.

And that ladies and gentlemen is how careers in physics are started,ps. I too once did the same exact thing, in fact the water in my syringe was cold, I guess to make sure the thermal shock is good enough... sure back then I did not realize that :D

 

[arydberg]

The fixture should be rated for a max wattage bulb. What is it? It should be printed on the fixture. My guess is that is was 60 watts and a 100 watt bulb was too much.

 

[nettleton]

Yes; a quartz halogen, in an approved reading lamp exploded, when I was not near it. The fragmnts were so hot, they burnt holes in the carpet.