# Conventional FixturesGels for Art Piece with a 500-Watt Halogen

#### LeeMiro

##### Member
I am restoring a light sculpture from the 70s and hoping you all might supply me with some basics on gels. Short version: Can you recommend a line of gels that I can safely use with a 500-watt halogen bulb? The long version has background on the sculpture and the safety issue . . .

The sculpture is one of my father's from his early artist career. It is a flood light retrofitted with green plexi in place of the usual tempered glass. It has two timers that sync up randomly, plus a delay relay that turns off the light after 10 seconds. The effect is the room is briefly flooded with intense green light at random intervals.

The original has a safety issue. Although the light turns off after 10 seconds, a failure of the electronics could result in the light staying on indefinitely and causing a fire. (It's a 500-watt halogen pointed at plexiglass.)

These lights haven't been run in years, and I want to bring them back into commission. My plan is to rip out the flammable plexi and replace with a theater gel placed over tempered glass. Does this sound reasonable? Should I be looking for gels with higher heat resistance? I see that Lee's High Temp Filters are rated to 220 C.

I don't have a way to measure the heat produced by the halogen bulb, but it's currently 1.75 inches from the plexi cover.

Photos of the piece below for reference. Pardon the appearance--it's been sitting in a garage for decades.

#### Amiers

##### Renting to Corporate One Fixture at a Time.
If you put the gel on the outside just replace it when it starts to lose it’s color.

500w at 10 seconds won’t hurt it. Even if it stays on all day until you notice the guts not working.

#### derekleffew

##### Resident Curmudgeon
Senior Team
These lights haven't been run in years, and I want to bring them back into commission. My plan is to rip out the flammable plexi and replace with a theater gel placed over tempered glass. Does this sound reasonable? Should I be looking for gels with higher heat resistance? I see that Lee's High Temp Filters are rated to 220 C.

#### JD

##### Well-Known Member
There is another alternative that would allow the fixture to stay exactly like it is but make it safe. Simply install a thermal fuse or thermal cutout in the fixture. If it were to stay on, the fuse or cutoff would shut it down when it started getting hot.
If it is only meant to be on for a few seconds, then you could used something pretty low in temperature, Maybe 100c. Thermal fuses are pretty cheap, you could pick up several in the 80 to 120 degree range and see if it works with the lowest.

#### derekleffew

##### Resident Curmudgeon
Senior Team
Not sure what part of CT you're from, but in Central CT two local places are Show Lighting Corp. in Berlin, CT and Advanced Lighting & Sound Solutions in Manchester, CT.
OP is in Hartford. Perhaps you have some roughly 6"x12" "scraps" of R93, R23, R68, and/or a Lux swatchbook, you could "lend" for the good of advancing art.

RonHebbard

#### LeeMiro

##### Member
I think it depends on how long it's going to run. A piece of dichroic glass that big would cost at least \$100. So if it's going to run once a week for a couple hours then it's probably not worth it. But if it's going to sit somewhere and run 24/7 for years then the glass might be worth the expense.
I've just plugged in the lamp to see how often it goes off so I give you all specs on the total amount of time it's on in a day. A permanent material is ideal, but I could always save extra gels if I need to replace it down the road.

Rosco, Lee and Apollo could all make a piece of colored dichroic glass to fit your fixture, but the colors are much more limited than gel. Dichroic glass reflects heat back to the lamp, so I suppose the lamp might not last as long. Another possibility is Gray/Devon Glass. The Devon isn't dichroic. I believe it's thicker, but that's probably not a problem in this application.
Dichroic glass is another material that's new to me. You say that the glass reflects the heat back to the lamp. . .Would this would significantly increase the heat in the enclosure (which is made from particle board and laminate, and ergo flammable) Or would the fixture casing absorb most of that heat?

There is another alternative that would allow the fixture to stay exactly like it is but make it safe. Simply install a thermal fuse or thermal cutout in the fixture. If it were to stay on, the fuse or cutoff would shut it down when it started getting hot.
If it is only meant to be on for a few seconds, then you could used something pretty low in temperature, Maybe 100c. Thermal fuses are pretty cheap, you could pick up several in the 80 to 120 degree range and see if it works with the lowest.
Thanks, JD. This was my father's thought--just add a thermal shut-off. It would totally work. I think my cautious nature prefers removing the hazard entirely, but it's definitely on the table, especially if I have trouble matching the original colors.

Also, Apollo makes a heatshield that can be used between the lamp and the gel that will extend the life of the gel. Dichroics would last forever (until broken).
That sounds great. Would that let me get away with mounting the gel directly on tempered glass?

Not sure what part of CT you're from, but in Central CT two local places are Show Lighting Corp. in Berlin, CT and Advanced Lighting & Sound Solutions in Manchester, CT.
I'm in the Hartford area, so both of those stores are definitely do-able. Thanks!

I will report back this evening with the frequency of the lamp turning on. That should help figure out gel vs. dichroic glass or Lexan. Really, the most important things to me are 1) preventing a fire in the event of an electronics failure 2) matching the color to maintain the original as much as possible.

#### bosox242

##### Member
OP is in Hartford. Perhaps you have some roughly 6"x12" "scraps" of R93, R23, R68, and/or a Lux swatchbook, you could "lend" for the good of advancing art.
I have R23, R68 and/or a Lux swatchbook I could give. @LeeMiro, let me know if you're interested.

#### microstar

##### Well-Known Member
fxlight.com makes a selection of heat-resistant color media products including Fade-not X gel. They say they can match to any gel color. Interesting website.

#### LeeMiro

##### Member
I've had the light sculpture plugged in for a while now. The light turns on for 10 seconds every hour, so a total of 4 minutes daily, or about 24 hours of on-time in a year. [Edited to add: I figure I will leave it plugged in.]

I still don't know what temperature my 500-watt halogen would reach if it didn't shut off, but looking online, it's probably about 570 F. Another source says as high as 1,200 F. As it's a 1970s halogen, it's hard to know.

With this in mind, do you guys have guesses on how long would a gel last?

Thanks for the link @microstar ! I'm checking it out now.

@bosox242 Thank you for the offer! I may take you up on that. My first stop will probably be to the shops you mentioned in Berlin and Manchester to see what they carry.

Last edited:

#### gafftaper

##### Senior Team
Senior Team
Fight Leukemia
The Gel is pretty unlikely to melt if you put it on the outside, but colors will fade over time. I would go with a layer of Apollo Heat Shield (which is clear and protects the color gel) and then a layer of the color you want. Send a private message to @Kelite (from Apollo) he will help you find a local Apollo dealer. If you are lucky he'll send you a gel book too. Remember with Gel that you can use two layers to make your own colors. I would take a gel book, tear it apart, and hold different combinations of gel in front of a light until you find just the right color you want. Don't try to judge based on what gel itself looks like, you need to see what it looks like with light going through it.

#### LeeMiro

##### Member
[
The Gel is pretty unlikely to melt if you put it on the outside, but colors will fade over time. I would go with a layer of Apollo Heat Shield (which is clear and protects the color gel) and then a layer of the color you want. Send a private message to @Kelite (from Apollo) he will help you find a local Apollo dealer. If you are lucky he'll send you a gel book too. Remember with Gel that you can use two layers to make your own colors. I would take a gel book, tear it apart, and hold different combinations of gel in front of a light until you find just the right color you want. Don't try to judge based on what gel itself looks like, you need to see what it looks like with light going through it.
Great, thanks! That's super helpful to know about layering gels. I'm going to take a look at the dirchroic glass, devon glass and this FX Fade-not, too, but a gel might be simplest. Is this the Apollo Heat Shield? I also see the Smart Color Pro 10. Not sure what the difference is.