Exterior Backlit Signs

[BIG EASY DOES IT]

acylic sucks, we use all lexan now. acrylic is brittle cheap. lexan looks and holds its white color longer

Acrylic is a material and Lexan is a brand. They are different materials but Lexan is just polycarb. It's like Jello and Gelatin.
There are uses for acrylic where polycarb would be the wrong choice.

 

[MikePro]

+1 to above, but i still say lexan all the time despite also using brands like makrolon.

although it was my understanding that acrylic yellows much slower, if at all, than even the polycarbonate that is treated with UV resistance as it is completely inert in solid form. china crap stuff, mmmmaybe? I've never had to replace a white acrylic face from yellowing BUT plenty of replaced acrylic faces from cracking/shattering.
fun fact: the acrylic windows in the canopies/bubbles of WW2 bombers are still clear after 50 years in the sun.

 

[Bobas Kalobas]

I have just recently did a few exterior Backlit signs for our company and the signs look yellowed when lit up at night. It is just cut vinyl on white 7328 Acrylic sheets, and a couple of them were done using P95 for a separate sign. Here is the kicker, On the first set, there a is large panel at the very top of the same monument sign that has been there for appx 10 years but it is white as can be when lit up from the same bulbs. The three panels I just did below it look like the older signs and they are brand new!! Did I use the wrong acrylic on both sets of signs? It makes no sense to me, the sign are brand new white acrylic signs. Can someone point me in the right direction please?

Sell them all new LED lighting for top & bottom so everything will coordinate. And possibly have to replace that bottom plastic with SG10 modified acrylic because that plastic may be the problem.

 

[ColorCrest]

Let me be clear here, CWHO = YELLOW, DHO = WHITE.

To be more accurate;
Warm White is YELLOWish (~3200k),
Cool White = GREENish (~4100k),
D50 = WHITEish (~5000k),
Daylight = BLUEish (~6500k).

One can usually see these different colors when the lamps are illuminated side-by-side. Daylight balanced color photography film certainly does.

 

[Chris Keena]

My fault for resurrecting this old thread. I have a new client asking to replace his sign because of hot spots. I'm going to work on getting the info and photos before I reach out for help. What I do know is that the box is decades old with a flat sign face, not pan face. Waiting for him to report what bulbs are inside before I head over to inspect.

 

[Chris Keena]

No worries, honestly its never bad to look back over old stuff, and it's always fun to watch everyone follow suit, as if this was a new thread the instant you posted!

So I asked the guy to send a photo of his light box, (attached). He's asking if there is any way to fix the hot spots. Says at night, all you see is the three light bulbs. Box looks like it's only 3-4" deep. Do you think a pan face would fix it? If not, I'm going to recommend LEDs or a new light box. Thanks.

 

[Andy D]

A pan face would help, but LED would be a better option IMHO.

 

[Andy D]

Overall that box is a joke, no offense. It looks like it was made from two smaller signs, used uncoated fasteners, the brackets across the bottom were too long and never trimmed, plenty of other stuff.
I'd argue the opposite, this can looks fairly shallow, and to get it lit uniformly would probably be way too many modules for the customers taste, especially considering the appearance of the cabinet in the first place. I'd jump on a pan initially, then come back with a different cabinet built 10" or more deep.

I should have elaborated, investing into a new Pan Face for that sign would be like putting lipstick on a pig & as sure as s**t, once you replace the face something would go wrong with the electrical and you would be blamed.
LED would still hot spot some but would be much more spread out , making the sign more readable than how it is now & would be a cheaper and quicker band-aid. You can also use the LED lights and transformer once they're ready to pony up for a decent cabinet, as JBurton said.