eppoxy in extremely high temps??
 

during weekends I fly rc..

weekdays I am a sound technitian and repair tech of profesional moving lights for concerts etc. (eg tonight I am working at the madona concert in Valencia)

My question is this...

In moving lights, the colours are created by graded filters being slid into and out of the light beam inside the fixture.

At time the plastic holder un-glues from the coloured crystal (called a diacroic).

can anyone give me any insite into if a model-grade eppoxy will hold up to high temeratures.. generally this will be around 10cm from a gass filled lamp burning at 5600 kelivn...
There is ventilation and saftey glass to reduce temperature between the lamp and these colours, but when the lamp is turned off, it is at LEAST 10mins before these glass sheets are touchable..

I dont have a thermometer usable for finding the temp so cant give any more accurate readings!

So.. when these un-stick. we use a mixture of cyano and high-temp silicon (we mix and apply it like eppoxy) but honestly I´m wondering if pure eppoxy would be stronger???


"I thinks" and "possiblys" arent usefull to me, if it goes wrong, generally in my work, it goes wrong live on TV, so I preffer answers only from people who are SURE.


Many thanks in advance.

RE: eppoxy in extremely high temps??
 

You can seperate two epoxy glued surfaces with a heated xacto knife, so I am thinking for your application, the awnser is no it will not work. Good Luck, Dave

RE: eppoxy in extremely high temps??
 

Gotta agree. I have used a hot air gun to remove thick fiberglass from a wing. It peeled up slowly.
Edwin

RE: eppoxy in extremely high temps??
 

high temp epoxy ( not modle stuff) can go to about 700F how about maybe a ceramic glue should be good to about 2 000F ...

RE: eppoxy in extremely high temps??
 

With freak, you can get high temp epoxy, used to make composite exhaust pipes among other things, but it won't hold up to 5K kelvin. Not a I think or a possibly... it won't work if the temp really is 5K kelvin. You're probably better off using the CA and Silicone you are using now.

RE: eppoxy in extremely high temps??
 

That is hot!

According to wikipedia

5.6k kalvin = 5326.85 C or about 9621F

RE: eppoxy in extremely high temps??
 

I think there was an extra zero in the kelvin measurement given. 9620F seems a litlle high. I think all kinds of things would melt by then, let alone epoxy. 560kelvin is 548F

RE: eppoxy in extremely high temps??
 

No, he really means 5600 K. That's how they define colors in high tech lighting systems. The Gas in the bulb is at that temperature. The surface of the light is significantly lower, but its still far hotter than our epoxies will handle. Hes better off contacting the manufacturer and determining the correct product to repair the filters.

Brad

RE: eppoxy in extremely high temps??
 

Yeah, I know he means 5,000 not 500, but even out at the lens distance, I'd think it would just be too hot for any epoxy I'm aware of, including the ones designed for high temp applications.

RE: eppoxy in extremely high temps??
 

JB Weld would probably work. It used to be used on the old Rossi mufflers that would fall apart from vibration. I tried to take one of these apart after having used JB Weld on it. Normal heat wouldn't do it. I finally had to use a propane torch to burn it off and that took quite a while to do it.

http://jbweld.net/products/jbweld.php

RE: eppoxy in extremely high temps??
 

When you use the phrase..Kelvin temp... you are not talking about how hot or cold something is. It is a term to describe the color of the light. It has nothing to do with how hot something is.

RE: eppoxy in extremely high temps??
 

Sure it does, it is the temperature an ideal black body would need to be to emit that color of light. I knew all those 400/800 level physic classes would pay off someday. :D

RE: eppoxy in extremely high temps??
 

I'm a gunmaker by trade. There is a resin system manufactured by Devcon called Devcon Titanium.

It's not cheap, but from what I remember it tolerates temps pretty well.

Hope this helped.

RE: eppoxy in extremely high temps??
 

Thanks i'll look into devcon..

the cyano/silicon mix is recomended by the manufacturers but once I have done this, they always return to my workshop as they unstick in a few months.....

The 5600k measurement relates to the colour AND the temperature, however it is only the temperature of the source of light, in this case the gas. Eg in normal fillament bulbs, the fillament is around 3200K but the glass does not reach anywhere near that!
9
The temp where these diacroics is definately nowhere near that range, as there is a protective glass between the bulb and them, (for heat and UV light prevention)


I'm currently trying to beg/borrow/steal an electric theremomiter suitable to measure and so, have a better Idea of what I can use......

RE: eppoxy in extremely high temps??
 

You can get Type K thermocouples with small leads (two ø0.2 mm dissimliar wires, side by side) that would probably go in there pretty well. Then you'd need a signal conditioner, small handheld ones are available.

Once you know the temperature, the adhesive folks (space shuttle tile adhesive, etc.) can get you the proper stuff. Probably worth the effort to measure. You might check with Omega or some thermocuple supplier, they may recommend a different thermocouple, and they may have adhesives for potting instruments like that handy.

Good luck,
Dave Olson