What are the issues with laminating a large enclosure MH bulb on the backside with aluminum foil held on with a metal tension band? (not overly tight, but the foil smoothly applied)

It seems to be a great, even reflector when I start the lamp, but before I go further, I wondered if anyone had bad experiences ... like fire and death. heh

Hmm maybe it is just a matter of seeing what happens eh? heh Covered and fire alarmed that is.

Since people routinely wrap stuff like potatoes in foil and throw them on a BBQ without incident, I don't think you need to worry about anything happening to the foil itself.

LOL so true. Bulbs on the barbie!

I have it fired up, and it certainly makes a great reflector on the big ole bulbs. I will get a picture later.

melting point of aluminum foil is over 1200*F.. however, some have reported light boxes near the bulb exceeding 800*f.. I guess you can try and see

what a thought! I think ill try that. What are you using to make the foil not fall off??

I basically shaped an unpainted coat hanger into a very elongated ellipse, then wrapped that around a softball ... and a little hand-bending. It acts like a tension belt around teh middle of the lamp with just a light pressure holding it above and below the midsection. It does not extend into the cone of the light in front, and the coat hanger does not touch the bulb ... only the foil. I used a foil rectangle slightly large than needed for rear reflectivity, then mapped/smoothed it to the back of the bulb. The tension belt is on top of that holding it all snug and flat against the bulbs rear.

It seemed to me that I got a big boost in my brightness. This will probably only work well with the football shapes, though. Their midsections are nicely spherical.

its pretty thin.. i would think it would melt if it was touching the bulb.. especially over time..

And it will most likely let off some smoke when it first gets hot.. its got stuff on it that burns off..

Well aluminum conducts heat, but doesn't store it. Most of the heat will just pass through. Example, you cook something in foil in the oven at 450*.. take the item out and the foil is cool to the touch after a split second. If the surface of the bulb exceeds 1200*F, which it very well may, this is not a good idea. Otherwise, you should be fine.

It will melt on any of the small shell lamps nothing should touch the lamp shell on the small shell lamps. That would be the FC2 lamps and the T15 lamps and the s400dd.

A large Ed28 or larger might be OK if you use a hevy foil.

I have melted some in an instant with a halgen lamp.

Well, I had it on all day long, and it looks the same now as it did when I put it on, so at least that is one positive thing for elephantine lumenairy faction!

I watched Underworld tonight ... a very dark movie ... and I really felt like the blacks were black, the details could be seen and the brightness was where it should be. All in all, I am very pleased.

Attached is a picture of my ever-so-trailer foil job. It's like my golf swing or a hooker ... she ain't pretty, but she gets you there.

blah I'm jealous of people who finish projectors so quickly I want to watch a damned movie! I have not watched one other than on HBO since I started my PJ. I don't believe in movie sex before marriage of PJ and screen

I have an Osram HQI 400 bulb(now a spare) with aluminium foil fused into the glass. I suppose things like this happen with experimentation.

I do.

Weldon - Are you still using this setup? If so, have you seen any change in the foil?

Yes, I am, and I have seen no discoloration ... though I think I will swap it out soon, because I have nicked it so much during pj construction.

I am still quite happy with it.

Wow... that lamp is HUGE. Compared to my 4 inch...

Mathinks lamp envy. Nah...

Thanks, tiny elvis! heh

It's only $17 too. Suck that, Samsung!!

before you completly take it off would you be able to post some pictures comparing the difference between the foil on, and then the foil off. to see the brightness change? thanks

I feel you man. I got rid of my Sony Wega on the 1st of October and I was going to have the PJ built by the end of Oct. Well a bunch of BS expeses came up which made is so the first spare cash I had was last week when I started ordering parts. It seems I have once again forgotten about some of these expenses and now I have to wait until Friday to get more money (it seems that in my ordering fury I overdrafted my checking account with all of the ACH transfers thru PayPal) Even this first *Budget* build is going to end up costing me close to 1K! I have ~$700 into it already.

Long story short my entertainment for the past month and a half has been watching Law & Order on usa on an old JVC SDTV.