What would cause a light bulb to explode?

Discussion in 'Community Discussion' started by Benjamindaines, Oct 20, 2008.

  1. macrumors 68030

    Benjamindaines

    Joined:
    Mar 24, 2005
    Location:
    A religiously oppressed state
    #1
    Last night I was watching Indiana Jones and the Kingdom of the Crystal Skulls (longest title ever!) when I hear that loud BANG; I got up and looked around the house and didn't see anything wrong so I went back to watching my movie. This morning I went into the bathroom and noticed that there was glass all over the sink and that one of the light bulbs was gone (save for the metal bit still in the fixture). What's really stumping about this is that the light was not on when it exploded! A bit like spontaneous combustion, but in light bulb form. It was just an ordinary filament light bulb (60 watts I believe); one of the round bathroom styles ones. Does anyone have any clue as to what could cause a lightbulb to explode when there is not power running to it? :confused::confused:
     
  2. Moderator emeritus

    EricNau

    Joined:
    Apr 27, 2005
    Location:
    San Francisco, CA
    #2
    It wasn't on? ...Had it recently been on?

    The gases inside could have expanded (due to heat) and broken the glass.

    ...Just a guess.
     
  3. macrumors G3

    NT1440

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    Hartford, CT
    #3
    g-g-g-g-ghosts!!!


    ZOINKS!
     
  4. macrumors G4

    Rodimus Prime

    Joined:
    Oct 9, 2006
    #4
    first off remember the inside of a light bulb is at much lower pressure than the air around it which is where both the bang come from and the fact it keeps the bulb under constant load.

    At some more micro fractures appeared in the glass at some point. Because of the constant pressure the cracks kept growing to the point where they reach critical and the glass of the bulb failed and it went boom.
     
  5. macrumors 603

    SkyBell

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    #5
    This happened to me once. I think it had something to do with the rapid cooling of the bulb or something.
     
  6. macrumors P6

    iJohnHenry

    Joined:
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    #6
    Yes, a flaw in the glass, fractured due to heating/cooling.

    Take care removing the brass fitting. Some use a piece of potato, inserted into the cavity, to twist it out.
     
  7. thread starter macrumors 68030

    Benjamindaines

    Joined:
    Mar 24, 2005
    Location:
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    #7
    Hmm, well the bulb was actually a burnt out one I just hadn't gotten around to fixing.
    Perhaps it was weakened at the base and just fell out of the base?
     
  8. macrumors 68030

    ReanimationLP

    Joined:
    Jan 8, 2005
    Location:
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    #8
    Seems kinda like a waste of a potato.

    I use a pair of pliers.
     
  9. Moderator emeritus

    EricNau

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    Location:
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    #9
    Or an excuse to eat the unused portion. :p
     
  10. thread starter macrumors 68030

    Benjamindaines

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    #10
    And if you cut up the inside of your mouth, that just makes you a winner
     
  11. macrumors Core

    MacNut

    Joined:
    Jan 4, 2002
    Location:
    CT
    #11
    Remember to turn the switch off before inserting said potato.
     
  12. macrumors G4

    Rodimus Prime

    Joined:
    Oct 9, 2006
    #12
    read my post. It explains it. even being burnt out the micro fractures where there and growing. It just got past the critical point and it failed.
     
  13. macrumors 6502a

    Mammoth

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    Canada
    #13
    ..Explosives?
     
  14. macrumors G3

    Counterfit

    Joined:
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    #14
    Well, I found out the hard way that putting even a tiny drop of water onto a lit bulb will make it POP! :eek::eek:
     
  15. macrumors 68000

    Leareth

    Joined:
    Nov 11, 2004
    Location:
    Vancouver
    #15
    Wow

    freaky coinsidence

    I had a lightbulb explode today while I was taking a shower in the bathroom.

    little pieces of glass everywhere, which of course I had to step on.
     
  16. macrumors 6502

    Joined:
    Feb 24, 2008
    #16
    I remember that scene from Home Improvement. Quite funny. :p
     
  17. macrumors 68040

    Killyp

    Joined:
    Jun 14, 2006
    #17
    Why?
     
  18. macrumors 603

    wordmunger

    Joined:
    Sep 3, 2003
    Location:
    North Carolina
    #18
    I don't think that's what happened. Much more likely is that the damage was catastrophic at burnout time -- the bulb had already "exploded" and was sitting intact in the base, balanced precariously on its own shattered shards. Then at some point it just fell out and smashed on the counter, creating the second "explosion" later.
     
  19. macrumors 68030

    ReanimationLP

    Joined:
    Jan 8, 2005
    Location:
    On the moon.
    #19
    I believe 110v through a potato would make it explode or mash itself. Also could give you one hell of a jolt.

    I'm probably wrong though.
     
  20. macrumors regular

    Joined:
    Jan 10, 2006
    Location:
    Findlay, OH
    #20
    I'd actually flip the breaker. Can't be too careful.
     
  21. macrumors 6502

    brian9271

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    Next door
    #21
    I shot it with my bbgun
     
  22. macrumors 68040

    Killyp

    Joined:
    Jun 14, 2006
    #22
    Well I was hoping to get an answer from a potato expert, but that'll do...
     
  23. macrumors regular

    Joined:
    Sep 26, 2007
    #23
    I believe that one would turn off the breaker before using the pliers. (had to add this, because you just know someone would take this at face value and actually try it...)
     
  24. macrumors 68030

    Gray-Wolf

    Joined:
    Apr 19, 2008
    Location:
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    #24
    If you need to remove the broken part, use a rubber handle screw driver handle first, and it should grip it just fine and not get shocked, even if the power is on.
     
  25. Administrator

    Doctor Q

    Staff Member

    Joined:
    Sep 19, 2002
    Location:
    Los Angeles
    #25
    Wirelessly posted (holmes/3.10.1 (OnetSzukaj/5.0; +http://szukaj.onet.pl) QTEK S100)

    From the instructions:
    What You Need:

    1 raw potato
    1 knife
    1 replacement light bulb
    1 bag for trash/glass shards
    Gloves
    Protective eyewear
    Vacuum/sweeper and a dustpan
    Recipe using the remaining half a potato is optional ​
     

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