I have read in many PLOGS about Lexan UV shields or some such, and I did a search but could not find an apt answer...

it looks like a thin sheet of white paper that goes b/n the bulb and first fresnal.

How far off am I?

Thanks!

well its thin and goes b/w the bulb and collimating fresnel.. and thats as close as you got

lexan is a polycarbonate (think plastic). The XL10 type of Lexan used here is molded to a thin sheet and blocks UV rays which can damage the chemicals in the LCD panel, and also blocks heat. It can withstand high temps, but should not be placed too close to the bulb because it WILL melt if subjected to temps above 300*F. It may look white in some builds because the person hasn't removed the protective film. You can find it in the window section @ Home Depot, and probably Lowes.

Lexan is strong, fairly unbreakable, scratch resistant, and light. Its used in race cars as replacements for glass windows to save weight.

I just installed my lexan and on the back it says the max temp is 800*F. Are there different kinds or are the manufacturers way too optimistic about its limits? I'm just curious its not like it will ever reach either of those temps.

No way 800°F. That's impossible. You SURE it's printed that way? Where's it from?

Awesome!

I'm guessing its a lot cheaper than heat resistant UV glass or whatever?

around $10 for a 24"x whatever sheet IIRC

I was searching for an answer about Lexan also and what its for. So now I know. But I notice alot of projects without using Lexan. So is this just an option? Is there much difference with and without it? Or just like to said - to protect the monitor mainly?

Thanks!

Warren

It blocks a significant amount of heat and harmfull UV rays from reaching the LCD. UV rays will deteriorate chemicals in the LCD over time causing a loss of contrast and color definition. excessive heat will cause the panel to turn black. Without very good airflow and cooling design/implementation, you will need lexan/tempered glass to block heat.

It is first and foremost used for blocking UV from the remainder of the projector components. If you choose to NOT block UV then you are taking a calculated risk. Some opt to not use Lexan XL-10.

Edit: Beaten by tameone yet again!

I think I'll go with adding it in then. Thanks for the info!

I hope to start my project within 2-3 weeks when i can afford the Magnavox. We have one in our kitchen and my wife caught me looking at the back for the model and already started saying NNNOOOOOOOO! Guess I have to get another I'll be sure to start a plog with lots of pictures for others to see.

Warren

Muuuahhaaaaahaaaahaaaaaaaaa!!! Yet another assimilation!!! <rubbing hands together sinisterly>

Welcome to the dark side.

Polycarbonate; aka Lexan, Makrolon, Zelux, Apec, Hiloy, Calibre, Lupilonx, Naxell, Trirex, Panlite

According to Wikipedia it melts at about 267 degrees C, or 512 degree F.

LOL at least your wife was smart enough to catch you before it say had a bad backlight and hmm might as well use it for the projector instead of letting it go to waste... Might still work if there was a little electrical surge that supposedly only affected the monitor.

It's a good lcd though you'll be happy with it.

DM

I read that as "300 Lumens".

what? thats bright.. try 250