Exploding Mag 85

I dropped my Mag 85 with the light on. Well that bulb only lasted for another hour. Kinda figured that. Then I put a new bulb in it. I had only used it for a few minutes at a time and it seemed ok. I used the first bulb for 30 minutes no problem- head got warm , no problem . Unit has UCL glass lens and FiveMega reflector and battery holder. I was using the light for about 10 minutes. It had been inside house, not cold- no condinsation. Well it started to fog up inside. Every thing was real clean (I thought) them POP! like the bulb exploded. Glass turned white and broke into a lot of small pieces (not lens but bulb). Anybody seen this before? did I do something wrong? The battery was not freshly charged either. This time I cleanded up light and relamped it. I also heated it up real good with hair dryer to drive out any moisure as my Orings are siliconed real well and it wount leak. Comments?

NikolaTesla /ubbthreads/images/graemlins/ooo.gif

An Arc lamp is the Spark that takes away the Dark--

http://f2.pg.photos.yahoo.com/ph/tomw9sx/slideshow?&.dir=/c6ab&.src=ph

sum stuff
i pulled a glass out of the dishwasher once, and it cracked in my hand
the dishwasher still had it quite hot, and my colder hand hitting just ONE location on it, caused contraction on the One area (the rest of it was expanded from heat).
i broke it like putting hot marbles in cold water.

Quartz bulbs for HIGH temp lights will die very early with a White film if you get Human greaces on them.
i dont know if the "zenon" style of bulbs use quarts, or if that happens to some degree with glass.

Water evaporation causes cooling, also water contact, can cause cooling immediatally just from the difference in temperatures, when the water makes very good contact with a hot surface.

Bright white incadescent bulbs for flashligns are often Overvoltaged lamps, so they burn hotter, but shorter
Ex: 2.4V bulbs in 3V systems that run at about 2.6-2.8 for a while, depending on the battery chemistry.
so they already dont last long (overdriven)

a Bulb with no vaccume will glow bright, the glass will go White as the titanium and other metals oxidise, and die quite quickly
i suspect your second bulb was a defect of that sort, or the glass cracked.

so mabey one of them ideas has something to do with it

I se others have had this experiance as well:

http://www.candlepowerforums.com/ubbthreads/showflat.php?Cat=&Number=920788&page=0&view=collapsed&sb=5&o=&fpart=1&vc=&PHPSESSID=

I heated and cleaned finger oil off bulb this time- I remember warnings about finger prints on quartz pencil bulbs now.


NikolaTesla /ubbthreads/images/graemlins/frown.gif

An Arc lamp is the Spark that takes away the Dark--

http://f2.pg.photos.yahoo.com/ph/tomw9sx/slideshow?&.dir=/c6ab&.src=ph

Just a touch off topic, but one part of a job I used to have was to maintain equipment for reading microfilm. The machines all used halogen lamps. I learned very quickly never to touch a new lamp while replacing it. It only took one major POP! almost immediately after it was replaced. Fun to clean up after pieces of nearly molten glass were sprayed over the housing. These things ran at 12 volts in most cases, but at very high temperatures. And they got hot fast! Replacing lamps that failed for any reason always meant letting them cool for about 15 minutes before you started to work on them.

Basically, I found that there isn't a good way to completely remove the oil that gets on the lamp if you touch it. There's almost always going to be some residue if not from the oil, then from the cleaner. Also, no matter how many times you wash your hands, there's going to be at least a trace amount of oil on them.

Now I always use a clean rag to handle any bulb or halogen lamp.

i use a clean towel with alcohol on it to remove/replace.

Same here!! or try Goof-Off

The best solvent to use to clean halogen lamps is 70% isopropyl alcohol, according to an Osram publication I have. This should remove all traces of finger-oil.

Anyway, as mentioned in another thread, PR base potted lamps are more prone to having structural defects in the glass because one of the leads must be bent backwards, and this is a no-no, but it must be done.

Other than one ring-potted lamp which had finger-oil on it (in a place that I couldn't clean) I do not know of any of my ring-potted lamps or bare bi-pin lamps, which have exploded.

This is one of the reasons why I think that potting super bulbs into PR bases is not the best solution to building a super-bulb light. I understand that it is often the most economical (in the short run at least), but it gives me shivers to think of a 35 watt lamp in a plastic pedestal and potted into something which is only loosely held to center, and which will have an increased chance of exploding.

I ordered a few more bulbs for spares. I will be using clean brand new cloth to handle them in the future. I was out of isopropyl alchohol too but that is easily cured. I guess we are (no pun intended) really pushing the envelope with a set up like this but it sure is neat. Also I intend to warm up every thing with hair dryer to drive away any moisture before reassembly. To bad my reflector got sputtered with fragments but it still works well- I can't see any artifects. Moral of the story: Be careful-Delicate!

NikolaTesla /ubbthreads/images/graemlins/cool.gif /ubbthreads/images/graemlins/frown.gif