Mag11 bulb explosion

LeDfLaShEr

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Every since I converted my tired Mag2D into a Mag11 I couldn't have been more happy with the light output. I've used it around the house a bit and horsed around with it a bit at work.

Last night I'm actually using it at work to look for someone who didn't want to be found. I'd had the light on for about 15 minutes....on and off....All of the sudden the light went out....I figured the batteries had died and was ticked off as the batteries should have lasted about three times that long....

However, all was not lost, I pulled a small wonder from inside my shirt....some know it as the Lioncub, and finished my work.

I put my mag in the trunk of my car and didn't look at it until this morning. I was about to charge the batteries when I noticed that it was not the batteries that were out, but that the bulb had basically exploded inside the head of the flashlight- filling the head with broken glass and covering the reflector with white crud.

Now this bulb only had, at most, two hours of usage prior to it departing this earth. I love the light output, but I'm hoping future bulbs will be a bit more reliable. Even if I had a bulb in the tailcap to replace it, it's going to take some work to clean up the reflector well enough to use it again.

This bulb was potted, and I'm wondering if using a potted bulb is somewhat less reliable than using a straight bi-pin setup.

I'm thinking I'll replace the bulb with a ROP bulb and try out that setup. Seems that ROP users are pretty darned happy...besides, then I can say I made a ROP also. :)
 

andrewwynn

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see: http://hotdriver.rouse.com

or.. better: start here

In the tests i just conducted last night.. a 13W light (1/2 the output of an 1111).. pulled 78W at startup.. i would anticipate nearly double that for an 1111.. it no longer is a 'wonder why' to me that incan lamps tend to fail 'dramatically' at times.

I still favor the 1111 lamp.. the only one i've been able to get away with using w/o a regulator... obviously not always and for everybody. all my incan lights will have regs. soon.

-awr
 

leukos

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Not sure where you are located, but winter temperatures can cause failure of the superbulbs. :awman:
 

wquiles

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leukos said:
Not sure where you are located, but winter temperatures can cause failure of the superbulbs.
Makes sense since at colder temps the filament's resistance will be lower, and therefore higher current would flow until it warms up (assuming it does not explode!)

Will
 

Yooper

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I dropped a potted 1111 into my 2D-body ROP (uses 6 AA CBP1650's) and it's not nearly as bright as the 24W ROP bulb. The 1111 went back in the bulb drawer for now.

Winter temps being a problem also makes sense due to higher heat stress on the glass of the bulb - it's like taking a glass out of the freezer and putting it on a hot stove burner.
 

lexina

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wonder if anyone else has had the same experience? am kinda worried because my favorite light now is a Mag2C running a 1111 on 2X18650s (unprotected). i am also planning to run the 1111 on my 2D with 6 NiMh when my 8AA-2D adapter arrives.
 

CLHC

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I don't think it's uncommon that when hotwiring these bulbs in modified Maglites, one can expect some sort of bulb/lamp failure eventually. Maybe that's why we don't buy just one but a couple lying around for that "just in case" incident. Of course Your Mags May Vary accordingly!
 

bwaites

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Funny how the same things come up and no one can figure out how to do a search for them with the new search engine problems.

There was a huge thread about this almost exactly a year ago.

The explosions are NOT caused by filament problems, but by stress on the glass envelope.

While, VERY OCCASIONALLY, the BiPin bulbs will do so, the potted bulbs have failed in this manner MUCH more often.

I have inspected a large group of bulbs that have failed like this, and all of them were potted.(Ginseng, and maybe js, have had unpotted bulbs explode, but the numbers are miniscule in comparison to the numbers of potted bulbs that have done so.) I suspect that the potting process, which requires bending the pins, sometimes stresses the glass envelope and a microscopic crack forms. Under the right conditions, including lots of heat and perhaps a little moisture, the expansion of the glass envelope is uneven and it explodes.

A small, but significant, number of lamps are ruined in the process of potting, which is why group buys make so much sense. You don't take all the risk that your 2 or 3 or 4 lamps will be the runs that are damaged. My suspicion is that that damage is similar to what causes the explosions.

I actually did some experiments with lamps, knife edges, and weights, and it takes a lot to CAUSE an explosive failure on a typical lamp.

Remember, all these lamps are designed for different environments than we use them in, so it should be no surprise when they go POOF!!

Hope that helps.

Bill
 

LeDfLaShEr

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Just a bit of a followup since my first post was a bit incomplete.....

I'm in California...the temp outside was about 55 degrees with fog. The bulb didn't burst at startup, which is why I was sorta suprised. It burst after the light had been on for for approx. 20 seconds.

My mag11 configuration is running off 6 energizer 2500 Mah NiMh batteries. The batteries at the time of the bulb failure had been in the light for three days. The bulb was potted. The bulb probably had a total of 2 hours of usage.

Anyone have a spare Kiu bipin socket they'd like to unload on me? I'm certainly not ready to give up on hotwires and I agree that stress from potting the bulb may have contributed to its early demise.
 

Yooper

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LeDfLaShEr said:
Just a bit of a followup since my first post was a bit incomplete.....

I'm in California...the temp outside was about 55 degrees with fog. The bulb didn't burst at startup, which is why I was sorta suprised. It burst after the light had been on for for approx. 20 seconds.


Probably just took that long to heat up enough to finally break the glass.
 

andrewwynn

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when you look at the temperature gradients.. i'm amazed hotwire lights even work ;) My buddy lunarmodule did an interesting 'experiment' with thermal gradients by accident recently.. trying to clean a reflector on a warm hotwire light.. blew the sub-zero air from a canned air over the lamp and managed to blow the bulb.. good thing to be aware of!

Whenever i run a light with the lens missing i always have eye protection.. it's a scary thing.. especially with the osram 100W.. i typically put that under my workbench when test lighting it (i.e. measuring voltage live with the top off).

-awr
 

Icebreak

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LEDFLASHER -

Also, sometimes but not always an envelope failure will leave the filament intact.

I have made the following mistake a few times:

"It is generally not a good idea to touch halogen bulbs, especially the more compact, hotter-running quartz ones. Organic matter and salts are not good for hot quartz. Organic matter such as grease can carbonize, leaving a dark spot that absorbs radiation from the filament and becomes excessively hot. Salts and alkaline materials (such as ash) can sometimes "leach" into hot quartz, which typically weakens the quartz, since alkali and alkaline earth metal ions are slightly mobile in hot glasses and hot quartz. Contaminants may also cause hot quartz to crystalize, weakening it. Any of these mechanisms can cause the bulb to crack or even violently shatter. If a quartz halogen bulb is touched, it should be cleaned with alcohol to remove any traces of grease. Traces of salt will also be removed if the alcohol has some water in it.
Since the hotter-running quartz halogen bulbs could possibly violently shatter, they should only be operated in suitable fully enclosed fixtures."


From Donald L. Klipstein's page navigable from the sticky in this forum.

Eye protection, as AWR mentions, cannot be stated too often.
 
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missionaryman

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LeDfLaShEr said:
Just a bit of a followup since my first post was a bit incomplete.....

I'm in California...the temp outside was about 55 degrees with fog. The bulb didn't burst at startup, which is why I was sorta suprised. It burst after the light had been on for for approx. 20 seconds.

My mag11 configuration is running off 6 energizer 2500 Mah NiMh batteries. The batteries at the time of the bulb failure had been in the light for three days. The bulb was potted. The bulb probably had a total of 2 hours of usage.

Anyone have a spare Kiu bipin socket they'd like to unload on me? I'm certainly not ready to give up on hotwires and I agree that stress from potting the bulb may have contributed to its early demise.

I don't know if we'll ever see KIU sockets again but you can get a very well made $25 PR-to-Bi Pin drop in from fivemega so you can use the bi pin bulbs which are far more reliable. That way you can also use a ROP set up and a few other types of bi pin bulbs while you're at it.
 

juancho

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It is another possibility for your blow up that have nothing to do with the potting process.

The potting process is one of the MAJOR causes of bulb failure, depending on how ENERGETIC was the operator in bending one of the legs with pliers (so it touches the side of the PR base)

But it is ANOTHER POSSIBILITY and is MOISTURE!!
If a drop of moisture (water or chemical) hits the bulb it will blow up!

Where you get this moisture from?
From a not well cured base for the metalizing process (mostly can happen MORE in reflectors coated all over-inside and outside-)

I have had a few experiences with potted bulb failures myself, some of them that happened in SERIES, I have recorded, like this one:

eightbadbulbs.jpg

So, watch your reflector and your glass lens after running the light for several minutes, if you see accumulation of moisture in the glass or execive fogging in the reflector, be prepare for another blow up.
Juan C
 

LeDfLaShEr

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My bulb looks almost exactly like your bulb farthest to the right....it basically blew right in half. There was fog on the day in question, but it had just started forming and wasnt too think. There was no other moisture.....

I just attribute it to bad luck. I'm trying to get some ROP bulbs so I can try that out next. Can't wait to get my hotwire fired up again.
 

CLHC

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Since the discussion is on "bulb explosion," is it possible that there could be a violent enough explosion to cause Maglite head diformities?
 

Icebreak

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I don't have my facts straight at all, CHC. I would say no to cause any head damage though. I've never dealt with anything over 60W. The strongest bulb I've had explode was a WA1185. It sounded like a muffled pop. There's not enough hot gas to have the kinda of force needed to do head damage.

But. (here is where my numbers are just guesses) Let's say the filament is 3000 degrees and the envelope is maybe over 500 degrees. When an 1185, 1166, 1274 or 1318 explodes the shards of glass must be going several hundred fps. Maybe 300 fps? The shape, speed and heat are enoungh to embed the shards in the reflective surface of the Al reflector and slightly into the Al itself. They can also stick to the glass window and form poc marks. I don't think the poc marks are from force. I believe it is the tiny deliveries of very hot glass to a relatively cool window causing surface fractures.

You can see this on an exageratted scale by doing a little trick. Find a piece of glass or mirror that is going to the trash bin. Get a flint and stick it in the end of a cigarrette. Heat to red hot then using your other hand flick the molton flint at the glass. Very sparkley event. Where the bits of hot flint touch the glass poc marks are formed from the rapid heating of the pin point areas of contact with the glass. Tiny craters of all shapes will be there.

I'm sure the explosions from these WA lamps without a lens or head are dynamic enough to cause damage to humans but not to the torch heads.

I'd like to see a super high-speed film of a bulb explosion.
 

CLHC

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Thanks for that Icebreak!

Kind of like when grinding metal next to glass to get that "poc" marking. And YES! I too would "like to see a super high-speed film of a bulb explosion."
 

LeDfLaShEr

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The head of my light looks undamaged....however, I haven't cleaned it out yet. There is still a thick white film over the reflector and the head is filled with tiny pieces of glass from the bulb. The lens appears okay, but it pretty dirty/filmy so it's hard to be certain.
 
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