melting gel in one performance

pyrus

Member
So, this has been really getting on my nerves: after every show I keep getting holes melted in the gel on 4 instruments. The color is Lee 116, and between it and the lenses is 1 cut of Rosco 119 and one cut of heat shield (another Lee product). So far at least one of these instruments consistantly burns holes in the L116 about an inch and a half in diameter after every show. Does anyone know if this has anthing to do with the gel itself, or pernaps the instruments themselves? Personally I have never worked with Lee colors before and have never had this problem with any other color. In two instances now the L116 and the R119 have actually fused together and holes melted through both cuts.
 

gafftapegreenia

CBMod
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Logos

Well-Known Member
Re: meltin gel in one performance

Yeah, even with a fesnel it is possible to focus the lantern so the focal point is exactly on the colour. It will melt in that case.
 

David Ashton

Well-Known Member
Re: meltin gel in one performance

sorry Tony but you can't focus the Fresnel to burn out the gel, you will burn out the gel when it is on full flood and the lamp is in close proximity to the lens and then it is a straight thermal effect.
 

dj_illusions

Active Member
Re: meltin gel in one performance

the ones i really hate are the metal shield in the newer selecon fresnels and pc's if you are using a dark colour it burns through the gel really quickly because the grill creates a nasty heat trap. I am sure the girll serves a purpose but we removed them from all our lamps and I always do so with hired lamps!
 

Sean

Active Member
Re: meltin gel in one performance

So, this has been really getting on my nerves: after every show I keep getting holes melted in the gel on 4 instruments. The color is Lee 116, and between it and the lenses is 1 cut of Rosco 119 and one cut of heat shield (another Lee product). So far at least one of these instruments consistantly burns holes in the L116 about an inch and a half in diameter after every show. Does anyone know if this has anthing to do with the gel itself, or pernaps the instruments themselves? Personally I have never worked with Lee colors before and have never had this problem with any other color. In two instances now the L116 and the R119 have actually fused together and holes melted through both cuts.

First of all, what kind of unit? If it's a Leko, is it sharp? In from or out from sharp?
L116 comes in a "HT" (high temp) variation. My experience with most Lee gel has been if they make it in HT, it's worth the additional $1 per sheet or so to buy it. Please take note that the HT sheets are a different size--20"x22", not 20"x24".

Also, the suggestion of using a color extender is correct. That's what they are made for.

If it is cost-effective (as in, it costs labor-dollars to have to change gel, the light is hard to reach, the run is long) I also would recommend the Apollo Gel Shield. It is expensive (~$40ish per sheet) but worth it. We use it to protect scroller gel strings.

--Sean
 

Lightingguy32

Active Member
Re: meltin gel in one performance

Color extender as every one else has said. Also check to make sure your heat shield is mounted in the right direction. If it is facing in the wrong direction it will eventually burn through and might even be the cause for the loss of gel you are experiencing. Heat shield has two sides to it, if the wrong side is facing the source, then it will have to double filter every bit of light going through it, thus heating it up a lot and also allowing some of the damaging wavelengths through onto your gel. Also look at rosco and see if you can find some close or right on color matches, surface coated gels (like LEE) tend to burn through really fast if they are deep colors. That being said I would first check if you have the heat shield installed the right way.
 

derekleffew

Resident Curmudgeon
Senior Team
Premium Member
Re: meltin gel in one performance

Before color extenders we used to tape saturated colors on the front of top hats, works wonders. Also, this new device just won LDI Widget of the year, maybe you could steal the idea and rig up something similar?
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Logos

Well-Known Member
Re: meltin gel in one performance

sorry Tony but you can't focus the Fresnel to burn out the gel, you will burn out the gel when it is on full flood and the lamp is in close proximity to the lens and then it is a straight thermal effect.

I have on more than one occasion with small 500w (usually minuettes) fresnels succeeded in burning holes in the dead centre of gels with the fresnel on spot. It may have been a bench focus issue and the reflector may have been out of place but it happened.
 

Kelite

Well-Known Member
Premium Member
Re: meltin gel in one performance

Before color extenders we used to tape saturated colors on the front of top hats, works wonders. Also, this new device just won LDI Widget of the year, maybe you could steal the idea and rig up something similar?
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The Gel Miser will certainly save expensive and/or dangerous trips up the ladder, but why not just get one and try it, rather than steal the idea?

(There is more to this device than meets the eye...)
 

fosstech

Active Member
As has been stated, be sure your units are correctly bench focused. Back in high school we had a couple S4's that would burn through a cut of R59 in minutes. I bench focused them and found that the lamps were not even close to being centered in the reflector and that the had really hot hot spots. After the bench focus they could be on all day and not burn through that super saturated R59 more than normal.
 

derekleffew

Resident Curmudgeon
Senior Team
Premium Member
The Gel Miser will certainly save expensive and/or dangerous trips up the ladder, but why not just get one and try it, rather than steal the idea?

(There is more to this device than meets the eye...)
I only suggested "stealing the idea" because the OP has the problem now, and the ad says "Available first quarter 2008." Certainly not suggesting an infringement of Apollo's intellectual property rights, Keith.
 

Kelite

Well-Known Member
Premium Member
Certainly Derek, I can understand the issue is a present problem. Perhaps we can get a few demo units into this venue in hopes of solving the problem now- prior to Q1 of 2008.
 

phil000

Active Member
Re: meltin gel in one performance

Color extender as every one else has said. Also check to make sure your heat shield is mounted in the right direction. If it is facing in the wrong direction it will eventually burn through and might even be the cause for the loss of gel you are experiencing. Heat shield has two sides to it, if the wrong side is facing the source, then it will have to double filter every bit of light going through it, thus heating it up a lot and also allowing some of the damaging wavelengths through onto your gel. Also look at rosco and see if you can find some close or right on color matches, surface coated gels (like LEE) tend to burn through really fast if they are deep colors. That being said I would first check if you have the heat shield installed the right way.


...and the way to tell which side is which is?
 

phil000

Active Member
So, this has been really getting on my nerves: after every show I keep getting holes melted in the gel on 4 instruments. The color is Lee 116, and between it and the lenses is 1 cut of Rosco 119 and one cut of heat shield (another Lee product). So far at least one of these instruments consistantly burns holes in the L116 about an inch and a half in diameter after every show. Does anyone know if this has anthing to do with the gel itself, or pernaps the instruments themselves? Personally I have never worked with Lee colors before and have never had this problem with any other color. In two instances now the L116 and the R119 have actually fused together and holes melted through both cuts.

We had a similar issue with S4s on full for a whole 150 minute show (well most of it) through R27. What we did is benched them all the way out (it was backlight, so it barely mattered hard v soft) and put a cut of HS in the slot nearer the lens, and another sheet with the gel in the accessory slot...mind you, we didn't have apollo about to send us some nice protos to save gel just for fun...but hey...it extended the life ~4x to what we had before.

Good luck,
Phil
 

icewolf08

CBMod
CB Mods
Re: meltin gel in one performance

...and the way to tell which side is which is?
On the good expensive stuff like Apollo GelShield, the shiny side goes towards the lamp. This should also be the side with the color number sticker. With other brands you would have to read the info that comes with it.
 

Kelite

Well-Known Member
Premium Member
Re: meltin gel in one performance

That's right Alex, and if the Apollo Gel Shield somehow loses its sticker, an Ohmmeter will let you know which surface has been sputter coated.
 

Lightingguy32

Active Member
If I remember correctly gel shield (no matter dichroic (glass) or standard plastic) has a side that conducts and a side that is an insulator. Take a ohm meter and probe both sides, right now I can't remember which side it is that is supposed to face the light and which side it is supposed to face away, but I remember that after you do the conductivity test, the conductive side is what matters.
 

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