Film-Tech Forum ARCHIVE: Cleaning dust from xenon lamp and mirror

This is topic Cleaning dust from xenon lamp and mirror in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Jeff Stricker (Member # 224) on 02-19-2009, 05:08 PM:

Just acquired a nice (very low hour) 600 W Christie lamphouse and PS for my home set up. Many years of accumulated dust on the mirror and bulb. I don't think a lens brush will do the cleaning job. Suggestions, please. Thanks in advance, Jeff

Posted by Gordon McLeod (Member # 33) on 02-19-2009, 06:11 PM:

Soft brush with a micro vac to start with then a moist soft plush cloth then use 99% alcholol on the lamp

Posted by Tony Bandiera Jr (Member # 2365) on 02-20-2009, 12:36 AM:

If the mirror is glass, first give serious thought to replacing the bulb.

The lower wattage bulbs are under a bit higher pressure than the higher wattage ones, and by virtue of experience (not) gained by high volume production, are more prone to explosive failure.

Be very careful in handling that bulb, even if it looks perfect. [Smile]

With that said, take the time to completely disassemble the blower assembly, clean the blower wheel with hot soapy water carefully scrubbing without bending the blades. Clean the blower housing the same way.

Blow out the motor with compressed air, and oil the bearings with a drop or two of oil, let it set overnight then oil again with a few more drops.

Get rid of all dust and grime in the lamphouse interior, especially on all the wiring. Check carefully for any cracked or damaged insulation on wiring, and replace it with wire rated at 105c degrees (most electronic and appliance repair stores have it.

As Gordon said, 99% (or denatured) alcohol is good and safe to clean the mirror with. Use an old cloth diaper if you can get one, it will be super soft and absorbent.

I have a 4k Christie (CH-40) lamphouse that looked like it was for the scrap heap...after a very through teardown and cleaning it works and looks better than new, and the blower is super quiet.

I can also give you instructions to modify the focus control rod to get rid of that damn c-clip that always falls off. [Smile]

Posted by Jeff Stricker (Member # 224) on 02-20-2009, 02:03 PM:

Hi Tony and Gordon, thanks for your replies on this vintage unit. Got some denatured alcohol. The mirror shines like new now, and will check out the bulb after other preparations are complete. The power supply is single phase 120V XM450-1L (600 W), I've checked all diodes and lytics, and the wiring is in tip-top shape.

I've brought the supply up slowly on a variac and the no-load voltage with 120V AC input(in "HI" position) is approx 110V DC. Outside of transformer lamination buzz, I can see nothing wrong with the supply. Bringing the voltage up slowly over several hours will usually reform the electrolytics.

Got a question on the lamphouse wiring... the lamphouse is a small vertical unit, type BF5-L. 120 volt wiring in the lamphouse goes to the fan, hours meter, igniter and emeregency start switch. Should this 120V circuit be wiried to the power supply AC switch so it comes on when the PS is switched on? Or can this be wiried separately to keep the fan going after the lamp and PS are shut off? Will the igniter fire as soon as the 120 volt AC circuit is turned on, or do you need to press the "emergency start" button on back of the lamphouse to fire the igniter?

Sorry for all the basic questions, but have never used xenon before... only incandescent quartz-halogen in my short throw set up. Thanks again. Jeff

Posted by Tony Bandiera Jr (Member # 2365) on 02-20-2009, 03:42 PM:

Jeff, no problem, keep the questions coming, there are a lot of helpful folks here and you'll learn a lot. [Smile]

It would be best to power the 120 separately, so that you can keep the fan running to cool the bulb off. The ignitor won't try to strike the lamp unless the rectifier has the proper no-load DC voltage on the lamp leads.

Posted by Jeff Stricker (Member # 224) on 02-21-2009, 02:49 PM:

Many thanks, Tony. The lamphose is up and running. Only 60 hours on the lamp! All that remains is getting it mounted, and adjusted. [beer]

thanks again, Jeff

Posted by Tony Bandiera Jr (Member # 2365) on 02-22-2009, 09:25 PM:

You're welcome Jeff, glad to be of service. [Smile]