Bulb exploded

Yesterday (8/10), I received in the mail an A19 body extending tube and P91 lamp assembly, items I gleefully assembled to convert my 6P into a 9P. I ordered these parts from LPS Tactical. Waiting until dark, I took my new instrument into the back yard and turned it on, marveling at the white fountain of light pouring through the lens. It was beautiful indeed - 200 Lumens! I marveled for about 45 seconds. A sharp, cracking pop! jolted the flashlight and the light flickered out. It was sickening. I went inside, opened the top of the flashlight, and found myself staring at the still-smoking ruins of the shattered bulb. Tiny grains of glass had scratched and befouled the lens, and had also become strewn in the threads of the bezel. I don't know why this problem occurred. I had powered the light with three 123A 3 volt Surefire lithium batteries which came in the same package with the other items I had ordered. I did not abuse the P91 LA in any way. Was this just a case of bad luck? I'm calling LPS Tac tomorrow. Think I'll run into any problems getting a refund? Any hope I could persuade them to replace the damaged lens as well?

Yesterday was my birthday, which is an added irony.

Had you touched the lamp envelope with your bare fingers?

Richard

Richard -
My inexperience is showing again. What is a lamp envelope?

Originally posted by poalcat:
Richard -
My inexperience is showing again. What is a lamp envelope?

Click to expand...

<font size="2" face="Verdana, Arial">Sorry, I was trying to avoid using "glass" 'cause it might be quartz, but that clear thing that surrounds the filament and contains the xenon gas and lets the light out.

Oil from your fingers is a typical cause of this type of explosion. The heat of the lamp boils off the oils increasing the temperature at that point and ka-boom.

Most people don't know this, and, until recently, it was not a problem with flashlights. It has been known for a long time with the high-performance TV and theatrical quartz lights.

I think SureFire and everyone else should make a warning about this on their lamp assembly packaging. I always use several layers of facial tissue (aka "Kleenex") to handle a lamp if I must touch the clear envelope (like a bipin lamp in a MiniMag).

Cheers,

Richard

SF lamps blowing up is a fairly common occurence...Call Surefire...

--dan

Is it a halogen torch bulb? If you've ordered a replacement bulb treat it like you would a car headlight bulb, don't touch the glass part of the bulb, and if this is unavoidable, clean the bulb glass with isopropyl alcohol (tape head cleaning fluid is made from this.)
Halogen bulbs can explode violently due to the high pressures inside and the high operating temperature of the glass. See Don Klipstein's web site on http://www.misty.com for more advice concerning handling of these bulbs!

You will have to call Surefire, LPS can't help you with warranty claims.

Surefire will replace the Lamp and bezel, just tell them what happened, no long explanation will be required. They will send you replacements. The same thing happened to my M3 & Surefire replaced the lamp & bezel.

Nasty thing a blown bulb.
SureFire bulbs are high pressure and when they blow, they tend to explode.
The high temperature SureFire bulbs are run at mean that moisture, oils etc on the bulb can be more dangerous compared to your run of the mill MagLite bulb.

A call to SureFire should help you resolve your problem. Please let us know how you get on.

The rate of failures of flashlights according to the discussion board postings may not be a reliable sample of the overal failure rate, and therefore it is difficult to say from a sum of the postings that a product is either reliable or not.
There are exceptions to this.
Arc's products appear to have a very large customer base here at CPF, and a CPF Special Edition flashlight (sold to CPF Members) would also show up reliability trends.

Bulbs fail. The good news is that Luxeons and other technologies promise to be more robust and are likely to replace many of the smaller flashlights. Just how much more robust and abuse resistant Luxeons are remains to be seen.

Al

Thanks for all the info. I called Surefire this afternoon and they agreed, with no quibbling at all, to replace the lamp assembley and lens. They were unbelievably courteous. I was afraid I'd have to send them the exploded bulb, sales receipt, etc.

I don't know if I touched the P91 bulb or not. I do know I will never touch one in the future.

If you do touch a bulb, or a bulb gets dirty/wet/ etc etc, there are simple and easy ways to clean it up.

Alcohol helps...

Al

Al,
always remember to mix your alcohol with water ......

The great Don Klipstein recommends a 70/30 mix of Isopropyl alcohol and water. De-Ionised water would probably be best. That serves to clean away any deposits not soluble in alcohol. (Fingerprints contain salts as well as oils.)

On a personal note, I've noticed that even Isopropyl can leave clearly visible marks on reflectors. It makes it worse if you try to dry the surface faster by using heat or forced-air. So, preferably just leave the item in a warm, not hot, well-ventilated space.

Jahn

I have touched high intensity lamps on several occasions. Each time I THOROUGHLY rubbed (actually twirled) the lamp using clean tissues, repeating the process two or three times with clean tissues. I have never had a problem with these lamps.

Brightnorm

For a while I worked for a large semiconductor equipment manufacturer, and in some of equipment we used high power (2kW) lamps to heat wafers. Even though this equipment was used and serviced in cleanroom environments (i.e., by people wearing gloves), we always stressed that the quartz bulb envelopes should not be touched. Of course, despite these warnings, failures were still experienced, typically of the rather shattering variety. Interestingly, sometimes the bulb would simply blacken and bulge at a specific location until a breach occurred (at that location). The lamp manufacturers indicated that any contamination on the quartz surface could lead to either failure mode. Typically they weren't that concerned about moisture, since any moisture film would evaporate as the lamp heated up. They were primarily worried about oils from skin or grease from mechanical assemblies.

I don't know how the P91 lamp assembly is constructed, or even the characteristics of the lamp itself, but if you have to replace the lamp by holding the bulb envelope, Richard's advice about using a tissue to change bulbs is spot on. Probably good advice for any lamp replacement operation (it's what I do, just to be safe).

John

The style of SureFire Lamp Assembly we're talking about is this:
[Click]

The bulb is fixed (prefocused) within the reflector.

There is no real need to touch the bulbs at all, but accidents happen.

I find the best places to keep bulbs are in the flashlight, in the spares carriers, or in the packaging supplied by SureFire.

Al