Gel for Cyc lights - endurance

[Scenemaster60]

I have a question for those who are much more experienced than myself in this respect. In Altman Cyc Lights lamped at 1K I have on a couple of occasions gelled them with R67 for daytime and R85 for nighttime. After rehearsals were finished I re-gelled for the run since there was substantial fade/burn on the gel from the focus and rehearsal process.

Would I have had LESS of an issue had I used LEE HT gel such as HT118 & HT 119?

I realize that colors are not identical, but they are close enough in a game of horse shoes to not really be significant on light blue muslin!

 

[Colin]

I've noticed marginally better staying power with Lee HT in this situation, but the thing that makes the most difference is keeping the safety screen away from the gel. If your models are 10+ years old you probably have flat safety screens and the gel will get sucked onto the screen and fry faster. Two years ago somebody somehow lost half the screens for our 2002 vintage sky cycs and when I ordered more from Altman they had changed them so that the screen protrudes from the frame about 1.5". The new ones are more of a pain to put in the fixtures (less flexible) and the screen-to-frame welds are already breaking, but I've gotten much better life from dark blues using those. Way better heat dissipation without hot steel screen touching the gel.

 

[Scenemaster60]

Very interesting. The ones that I have worked with have always had the screens physically touching the gel. These are likely from the 1980s or 90s.

 

[Colin]

Very interesting. The ones that I have worked with have always had the screens physically touching the gel. These are likely from the 1980s or 90s.

Just looked up the invoice and I paid $19.14 each for the new screens. I hated the price at the time, but considering a sky cyc eats a full sheet of gel each time, an extra week or two of gel life might be worth the upgrade. Or melt the fixtures down for doorstops and get some half sheet fixtures instead...

 

[Scenemaster60]

Colin…. The trick is this…. Once the Cyc lights have eaten up a 16x16 cut of gel, you really can get four 7.5x7.5 cuts from these sheets for use in fresnels, S4 PARS, or PAR 56 fixtures by cutting the burned out spot into the corners!

 

[StradivariusBone]

We've got Sky Cyc's from the mid-90's and the frames do not have any screen on them to speak of. I've found this suspect since the quartz halogen lamps sometimes fail pretty aggressively. Do you have a link to where you paid $19? Everything I'm finding is $25+.

In any event we burn through anything blue in about 2 weeks worth of usage with a 1000w lamp.

 

[RickR]

Other gel saving tricks;
-heat blocking gel (R1995) between lamp and gel
-very light frost between lamp and gel
-perforating the gel with very fine holes for venting (ask the costumer for a perf. wheel.)

 

[Scenemaster60]

RickR, how would you use heat shield or frost on a sky cyc to any useful benefit?
I'm just not picturing how it could be installed in order to function properly.

 

[techieman33]

RickR, how would you use heat shield or frost on a sky cyc to any useful benefit?
I'm just not picturing how it could be installed in order to function properly.

You don't get the full benefit but it can help some.

 

[MrsFooter]

Other gel saving tricks;
-heat blocking gel (R1995) between lamp and gel
-very light frost between lamp and gel
-perforating the gel with very fine holes for venting (ask the costumer for a perf. wheel.)

Perfing the gel used to be standard practice in my venue, however, I put a stop to it. My experience is that it actually causes gel to burn faster, because it gives burnouts a place to start. However, I've never tried it in cyc cells, so results may very.

My experience with HT gel in cyc lights has not been a pleasant one. On the contrary, I consider it one of the bigger mistakes I've ever made. The problem with HT gel is that when it heats up, it has a tendency to shrink and crinkle. Even though I cut my gel at least 2" bigger than necessary, by the time it finished shrinking I had a row of light leaks that would make your momma cry. By the week's end, I had to replace every single cell due to melting and shrinking. Save the money and the headache, don't do it!

 

[RickR]

I'm curious if others have had MrsFooter issues. We know things vari from place to place, but I've never even heard of such issues, let alone such an extreme case.

 

[StradivariusBone]

I've had the shrinking problem and we use the Rosco cyc silks in ours, they all will eventually end up with light leaks, though the reds and ambers seem to do it faster. The blues just burn through before any shrinking happens. I feel like the silk might absorb more heat and cause it because when we've put regular gel in them on occasion, they just burn through like normal.

 

[techieman33]

I've had the shrinking problem and we use the Rosco cyc silks in ours, they all will eventually end up with light leaks, though the reds and ambers seem to do it faster. The blues just burn through before any shrinking happens. I feel like the silk might absorb more heat and cause it because when we've put regular gel in them on occasion, they just burn throw like normal.

We normally use cyc silk, and it does shrink some. Putting 2 brads in the frame on each side helps slow things down some.

 

[josh88]

I use Rosco's cyc silk too and in my fixtures at least (altman skycycs) I never actually burn through. But I do have the shrinking problem. Its tough to find budget for me to replace the gel so its usually only a once a year thing. Light leaks all over at the moment, and while it hasn't put any holes in it, its so crispy and brittle that once I do swap it out, it'll almost shatter.

I have screens, but they tend to just leave me with the cross hatch pattern melted into the gel. I have used heat shield but don't anymore. Didn't have mrs. footer's issue, but it didn't seem to do anything to help so I don't waste the money.

 

[Catwalker]

At my theatre, we have some 500w Strand cyc units (Strand Iris? I'm not quite sure). I don't think that the gels in those have been replaced, or even touched, since the theatre was built (11 years ago).

However, I recognize that you folks are talking about 1k units, and those probably burn through gel much faster.

 

[danTt]

I suspect that unless you have are gelled with R00, the color the light currently puts out is much much different than the color that it originally put out... even at 500watts you've probably burned through any useful color years ago.

 

[Calc]

I've got some of the Strand Coda 500-3's. Use the Rosco Cyc Silk, and end up swapping gel once per year or so with fairly light use. I do get some of the shrinking, but if you catch it early you can sometimes save the gel by re-seating it in the frame.
The Coda's keep the screen further in to the fixture, so they don't end up touching the gel. What I have started running in to is some of the internal terminal blocks frying. Lucky for me, Strand made a 4-cell unit and used the same parts, so there's an extra pair inside the fixture already.

 

[RickR]

RickR, how would you use heat shield or frost on a sky cyc to any useful benefit?
I'm just not picturing how it could be installed in order to function properly.

Anything between the lamp and the color will help. The main goal is to get better ventilation around the color. Frost will absorb a bit more IR than a clear gel.

Changing the convection currents is also the goal of the bowed out screens.

However the only complete fix seems to be LEDs, with it's own drawbacks.

 

[afreeradical]

As I sit here in show watching my R67 and R79 on @ full and burning completely threw in my 1K Altman Focus Cyc's, I too wish someone had some miricle fix. I've tried everything suggested here so far and do not think ìt gave me more than days.
One thing you can check is, if you have moveable reflectors like my Focus Cycs. That they are as far back as possible. You trade output for gel endurance

 

[StradivariusBone]

Does anyone here lamp the Sky Cyc's at 1500w? I've only ever used 1kW lamps.