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Author Topic: Xenon Bulb blowup damage the truth the myth? Paul J. Neuhaus Expert Film Handler Posts: 126 From: Iraq.. Again! Registered: Jun 2005 posted 06-14-2005 12:24 AM                     Hey everybody. What's the worst damage you've ever witnessed a Xenon Bulb do? The worst I've ever seen was a scored reflector that we replaced. I've heard stories about lamphouse doors being blown off their hinges and shards of glass sticking in block walls. Any Truth to the Matter?? Can they really be that dangerous?  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 06-14-2005 01:42 AM                        I once had a 2k bulb one blow up on me while I was removing it from a lamphouse (thanks to a faulty ammeter causing us to run it at way over its rated current, the anode lead had burnt out and the lamp had failed). The explosion was more of a dull thud than the big bang I'd been told it would be, but the force with which the envelope disintegrated was impressive. Several fragments were deeply embedded in my face mask, protective jacket and gloves. We were sweeping and hoovering bits of bulb up from all over the booth for days afterwards. If I hadn't been wearing the full protective kit, there's no doubt in my mind that I'd have been seriously injured or even worse. Another decision I made from that point on was that no-one in that theatre was going to be handling bulbs on their own. This incident happened after the last shows had finished and I was the only person left in the building. If, for example, the face mask had shattered... well, I think I used up one of my nine lives that night. In retrospect I wish I'd taken some pictures of the aftermath, but was too shocked to do anything mucn except clean up, switch everything off, go home and have a very stiff drink! Before that incident another bulb had blown in the same lamphouse. This happened immediately (i.e. within a couple of minutes) after the lamp had been struck for the first time after the theatre had been closed for three weeks due to flooding in the building's basement. The whole place was very damp, so I suspect that condensation on the envelope was probably the straw that broke the camel's back. In this case the lamphouse contained the blast: if I remember correctly, there were a few abrasions on the mirror (so much so that we retired it to a cupboard for use as an emergency backup, but it was still usable - just) and one or two minor components in the strike unit needed changing, but that was the limit of the damage. That having been said, the lamphouse was one of those huge 1970s Cinemeccanica things which was built like a tank and designed to hold a much larger bulb than we were running in it. In terms of damage caused, I guess that a lot would depend on how sturdily the lamphouse was built in relation to the size of the bulb. I imagine that a lamphouse made of flimsy sheet metal would not look pretty after an 8k bulb exploded in it.  |  IP: Logged Ferdinando Innocenti Film Handler Posts: 79 From: Genova / Italy Registered: Jun 2004 posted 06-14-2005 02:21 AM                     Well, this is (was?) a Prevost P93 just after a blowup of a 4000W lamp. Everything in the lamphouse was broken, except for the igniter. The wires from the rectifier were damaged too. Two blowers, IR filter, reflector, spring for the mirror, capacitor, photoled, wires, everything. But there was no problem outside of the lamphouse. If a lamphouse is good, there's no chance to destroy it with a blowup.  |  IP: Logged Frank Angel Film God Posts: 5305 From: Brooklyn NY USA Registered: Dec 1999 posted 06-14-2005 02:24 AM                        Not to go off subject, but the protective gear that I found in one of the booths consisted of gloves, face protection helmet and tyvec jacket. The gloves and the face mask/helmet seem like they would help, but I really question the tyvec jacket. Does anyone know if this flimsey stuff will protect from flying quartz projectiles of an exploded bulb? I'd hate to find out after the fact that they go through this stuff like a knife through butter. What do you guys use for body protection?  |  IP: Logged Robert John Jeromson Master Film Handler Posts: 264 From: Auckland, New Zealand Registered: Jul 2004 posted 06-14-2005 04:50 AM                     I have had three go in my carrer, two 5k's and one 7k, all made one hell of a mess, destroying the reflector and fusing reflector fragments to the surface of the anode. The coated heat filters survived (the 7k bang cracked it however) but the first 5k I had go dropped molten glass onto the floor burning small holes in the lino.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 06-14-2005 05:49 AM                        quote: Frank Angel What do you guys use for body protection? For the screening rooms in our building at Kodak, we use a one-piece KEVLAR jumpsuit with long sleeves and pant legs, and a high neckline that fastens around most of the neck. It's hot, heavy, and uncomfortable, but IMHO the safety is worth it. (To test its effectiveness, I tried piercing it with a sharp screwdriver.) We wear double eye protection: safety glasses with side shields, and then a full face visor. For the hands, we use chain mail meat-cutters gloves. I agree with Leo that you should not work alone when handling xenon lamps -- a "buddy system" is a good idea in case of injury. Again: If you don't wear the proper safety equipment to handle xenon lamps, an exploding lamp is likely the last thing you will ever see!  |  IP: Logged Mark J. Marshall Film God Posts: 3188 From: New Castle, DE, USA Registered: Aug 2002 posted 06-14-2005 01:45 PM                    I'll second that. A good friend of mine had one blow up in his face right after he disconnected the ground lead. Luckily he had a face shield on, but no other protective clothing. He had bloody arms and a neck, and he said his ears were ringing for about an hour. To this day he still has quartz shrapnel embedded in his arms and upper chest and neck. They even show up on an MRI.  |  IP: Logged Scott Manley Film Handler Posts: 59 From: Austin, TX USA Registered: May 2001 posted 06-14-2005 05:05 PM                     I had a 2K CHristie bulb once blew and little more than doubled the opening in the reflector  |  IP: Logged Phil Hill I love my cootie bug Posts: 7595 From: Hollywood, CA USA Registered: Mar 2000 posted 06-15-2005 01:28 AM                  At my former job "position" I was known as "Mr. destructo"... I have blown up more 7k, 10k, and 15k bulbs than I can count. ALL for good reason! It's ALL about cooling AND current! NEVER trust the published/manual specs for air flow for a lamphouse! While it is very important to cool a lamp properly (the envelope as well as the seals) it's equally important NOT to over-cool the lamp! BTW: Putting aside the better "optics" of glass reflectors... the metal reflectors provide much better protection to ALL the lamphouse components with a catastrophic bulb failure. I'll take metal over glass ANYDAY! And YES! I agree with all yous about wearing protection.. and I don't mean condoms unless we're talking sex here..  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 06-15-2005 02:22 AM                     ..what's interesting is how black the anode end and the cable is when that 4k took off in that Prevost lamphouse. Not enough cooling, and the front seal let go? That's one big "Ka-Boom!" -Monte  |  IP: Logged Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 06-15-2005 04:58 AM                     Xenons worry me (maybe that's where my hair went). I 've never had to handle anything bigger than a 2k, but I don't like doing it; I feel much safer handling a box of carbons. I've only ever known one to explode, it was and old three electrode thing many years ago, and thankfully I was in the auditorium, not up in the box.  |  IP: Logged Darren Briggs Master Film Handler Posts: 371 From: York, UK Registered: Dec 2001 posted 06-15-2005 05:12 AM                        After the incident that Leo decibed above where the lamp went after it had been on for a few minutes, the lamphouse looked like a steam train as shards of minute glass were blown out and everywhere. As the cinema was closed and we were all in the room, (One next to the Projector mech, I was behind the lamphouse and Leo at the desk) we all decided that the dust was not good for us and went for a Guiness i believe at the pub next door. It was a very loud bang indeed. Lamphouse still in use today, new miror and a meter that matched its shunt! (After calculations we were giving the 2k lamp 95amps, but the meter read 65, great picture for 500 hours though!) Darren  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 06-15-2005 03:25 PM                        quote: Phil Hill ...and I don't mean condoms unless we're talking sex here. I once saw my boss leave the 'condom' (i.e. the protective plastic sleeve in which a xenon bulb is shipped) on a bulb after fitting it and striking up (the xenon, that is!). For a second or two, he wondered why the picture looked dull; then there was a funny smell; then a couple of blobs of molten plastic dribbled out of the grille in the bottom of the lamphouse... and then the penny dropped. The bulb was obviously ruined - the quartz envelope would have been delaminated, for one thing - but it didn't blow.  |  IP: Logged Aaron Garman Phenomenal Film Handler Posts: 1470 From: Toledo, OH USA Registered: Mar 2003 posted 06-16-2005 02:34 AM                     I've got some darn thick gloves, a mask, but nothing for my body. Any ideas on what I could get on a modest budget? All these stories start to make me nervous, along with the fact that my work clothes consists of a short sleeve shirt! AJG  |  IP: Logged Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 06-16-2005 03:30 AM                        Someone I once worked with used an old leather motorcycle jacket (I think he fancied himelf as Dennis Hopper in Easy Rider, though the fact that he was totally bald sort of undermined that image!), insisting that it would provide better blast protection than the xenon jacket we had in the booth. Thankfully, that theory never had to be put to the test.  |  IP: Logged

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