Exterior Backlit Signs

[Artworks]

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?

 

[Artworks]

Here is a pic

I have attached a pic to this thread...

 

[Andy D]

How do they look during the day?
If it's your plastic, the top would be white and your
signs would be yellow during the day too. Looks to me like some of the bulbs
went out on the bottom, or different type of bulbs...
It's not lit up by the same bulbs, it doesn't work like that, there is at least two cabinets stacked on top of each other.

 

[J Hill Designs]

+1 bottom lamps are either partly dead, or DHO instead of CWHO

 

[Morkel]

When you say white acrylic, is it an acrylic that is made to be backlit (translucent)? We use "opal" acrylic (not "white") for backlits. If the acrylic has not been manufactured for being lit, it would definitely be duller and potentially off-colour.

If it's made to be backlit, then yep, 100% it'll be the fluoros behind it.

 

[ams]

Looks like a different color bulb. Ask the shopping center to have you replace them with the correct ones.

 

[HDvinyl]

I like the new ones better.

 

[reQ]

+1 for bulbs. When polycarb yellows, it still shows up white during the night if white color bulbs are used & would be yellow during the day time

 

[Randy101]

Top sign has Daylight lamps and the bottom has Cool White lamps.

 

[reQ]

Top sign has Daylight lamps and the bottom has Cool White lamps.

I think you wanted to say that top one got cool white, which is daylight lamps & bottom ones have warm white installed

 

[visual800]

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

 

[J Hill Designs]

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

that being said, new acrylic shouldn't look yellow unless there is a lighting issue

 

[Artworks]

To answer all of the questions, The bulbs are the same 4 vertical 8 ft bulbs that light all four panels. During the day, all of the signs are white. All of the bulbs are working properly.

EDIT: The top Bulbs are a separate cabinet, however, both sets of bulbs are working and are using the CWHO bulbs....

 

[J Hill Designs]

To answer all of the questions, The bulbs are the same 4 vertical 8 ft bulbs that light all four panels. During the day, all of the signs are white. All of the bulbs are working properly.

are the lower ones DHO or CWHO though

edit: reread. so that full sign is only 8' tall? with the extra black space below the top panel it looks like 2 separate stacked cabinets

 

[Andy D]

To answer all of the questions, The bulbs are the same 4 vertical 8 ft bulbs that light all four panels. During the day, all of the signs are white. All of the bulbs are working properly.

If you say so, that's not what it looks like to me, it looks like two cabinets and three H rails on the bottom cabinet. What's the separation between the top and the second from the top?
If it is all the same bulbs, then it could be the top panel was clear plastic with diffuser on the second surface.. I am seeing hot spots.
Or you could have used plastic that wasn't meant to be backlit.

 

[Gino]

So, those 3 signs at the bottom are around 18" x 36" each ?? Had me fooled, too.

Looks as though the top one used sign white acrylic or polycarb, while you used something a little different. Whatever you used is not allowing proper light transmittance, therefore creating a yellowed effect. That is, indeed, if they are all using the same lamp from top to bottom and the entire fixture is only 8' tall. To me, seeing the pole go up through the middle and the varying light colors, you should've used pan faces. Things are not reflecting correctly inside there.

 

[Artworks]

If you say so, that's not what it looks like to me, it looks two cabinets and three H rails on the bottom cabinet. What's the separation between the top and the second from the top?
If it is all the same bulbs, then it could be the top panel was clear plastic with diffuser on the second surface.. I am seeing hot spots.
Or you could have used plastic that wasn't meant to be backlit.

Sorry, Yes you are correct. They are two separate cabinets. Before I replaced the panels all of the signs lit up the same white. I had to replace one of the bulbs in the cabinet and it was a CWHO bulb. I will climb up today and further investigate the top bulbs and panel to see what it is made of.

If I wanted my signs to be that bright white at night, what material do you recommend? Those panels are the 7328 acrylic for backlit. That is what the manufacturer sold me for that application. I have also used sign white p95 on other signs...

 

[Z SIGNS]

looks like top panel is 2447 white

 

[J Hill Designs]

Sorry, Yes you are correct. They are two separate cabinets. Before I replaced the panels all of the signs lit up the same white. I had to replace one of the bulbs in the cabinet and it was a CWHO bulb. I will climb up today and further investigate the top bulbs and panel to see what it is made of.

If I wanted my signs to be that bright white at night, what material do you recommend? Those panels are the 7328 acrylic for backlit. That is what the manufacturer sold me for that application. I have also used sign white p95 on other signs...

slight color difference tells me you replaced the one on the right (from our perspective) yes?

 

[Andy D]

Sorry, Yes you are correct. They are two separate cabinets. Before I replaced the panels all of the signs lit up the same white. I had to replace one of the bulbs in the cabinet and it was a CWHO bulb. I will climb up today and further investigate the top bulbs and panel to see what it is made of.

If I wanted my signs to be that bright white at night, what material do you recommend? Those panels are the 7328 acrylic for backlit. That is what the manufacturer sold me for that application. I have also used sign white p95 on other signs...

Okay, that makes more sense.

You don't still have the panels you replaced do you?
If not, I would remove the retainer on the top panel and slide it out enough
to see if it's white plastic or clear with diffuser.
If it is clear with diffuser, it probably 30, meaning it lets 30% of the light through.
If it's white, show the picture to your plastic guy and have them give you a sample of what they
think would be best, and do a night time comparison.

edited to add: is the copy on the top panel 1st or 2nd surface? If it's 2nd surface it has to be clear with diffuser...