I can't believe this. I was working up in the loft in the shed when I bumped my trouble light. As always, there was a bright flash and the bulb burned out. They always burn out at the worst possible times. I was in total black, and getting down from that loft is no easy task. After saying a few 4 letter words I grabbed the light and was preparing to climb down from the loft. All of a sudden the light flashed on for a second, then off again. I shook the light and once again there was a very bright flash. I knew for sure the bulb was dead after that...... Or so I thought.... Still holding the light, I shook it again, not expecting it to re-light. Much to my amazement, it lit again. This time it was normal brightness, but as soon as I moved it, it went black again. This happened about 4 times, and then the light stayed on. I hung the light from a nail and proceeded to do what I had been doing, and waiting for another bright flash. I was almost done with my tasks up there and just hoped that the bulb would last long enough. I really suspected that as soon as I started to pound a nail with my hammer, the vibration would destroy the bulb. I finished pounding in about ten nails, and the light remained burning. I grabbed the light and proceeded down the ladder. The bulb remained burning. I hung it up next to my workbench and shut it off. I closely looked at the bulb. I could see the scrape marks in the inside coating where the filament had scraped off that coating. At least six very noticable scrapes. I was sure that as soon as I turned the switch back on, the bulb would burn out with a bright flash. I flipped the switch, and the bulb worked as a normal bulb......
This all happened a week ago. I've used that trouble light with that same bulb several times. I've moved it, banged it, and turned it on and off many times. I can tell the filament is loose because whenever I move the cord even the slightest, the movement of the filament is visible. I have been carrying around a new bulb, but I dont plan to install it until this bulb really does burn out. I simply can not believe that a bulb that burned out with a bright flash TWICE, and shows all the scratch marks on the glass from a dangling filament, is still working and apparently healed itself. I have never seen anything like this...
Mark