exterior sign advise needed

[Bill Maietta]

I recently donated some work for a local community health center. I built some counters and a cabinet along with a sign that also serves as a partition (pics below). I only did the initial sketches of the sign. A real sign designer came up with the finished product, which I think turned out great.

Now they need an exterior sign, and I am suggesting using the same design. They want it in a lighted box, and they have a good metal-worker/welder who is going to build the box. I'm wondering about a few things. Is polycarbonate a good way to go for panels on either side of the box? And lighting, a strip of LED cord light? One idea from the guy building the box was to loosely pack spun glass in the box to help diffuse the light. I wonder if this is feasible, or if there's another practice to get an even light distribution. The sign will be 28" x 60".

I apologize for my naivety on this. Furniture and cabinets I can do, but I'm about as new to signs as possible. Thanks for any help you can offer.

Bill

[Joe Pelonio]

Yes, polycarbonate is the best material, doesn't crack from vibration/impact as easily as acrylic. Normally that box would have 2-3 tube fluorescent bulbs, set back far enough that no diffusion is needed. You will want to ask for sign white material. LEDs will be much more expensive but save them on the electric bill. The real problem is that the local sign and building permit agency(ies) will probably require a licensed electrician to install it, and a UL approved fixture. If you make it and install or they install and it's not permitted they can be fined and made to remove it. If you are in a small unincorporated town where no one pays attention to these things you might be OK, but even in small cities like ours they are very particular about the sign location, colors, installation method and get several hundred in permit/inspection fees.

[Bill Maietta]

Thanks Joe. I will check with them about the permitting requirements.

As for setting the bulbs back far enough, if the box were 8" across with bulbs centered, would that work (given sign white polycarbonate)?

[Don Nicholas]

Joe is completely correct. One thing you may check on does the city require the sign
Required to Have a UL sticker.
Some sign companies have a stock of used signs that could be used, refurbish the electrical and they would supply the UL sticker.
Good luck with your project.

[Bill Maietta]

So, I have checked with the guy I'm helping with this, and yes, he has already run his ideas by the inspector. It's a very small town, and he has worked with the inspector a lot in the past. He also is planning on using LED lights (e.g. low voltage) run off of a small solar collector on the roof.

The 2 important questions I have now are:
1. how narrow can the box be to properly illuminate white polycarbonate sign panels on either side with LEDs? He is planning on building a 28" x 60" box, and he would like it as narrow as possible.

2. can he attach LED bulbs to a screen centered in this, hopefully narrow, box and use spun glass loosely packed to fill the box and help the light appear even?

Thanks again

[Joe Pelonio]

Sorry I can't help with that. It can be thin since LEDs don't heat up but they tend to be narrow spot light rather than flooding the background. That's why even a flashlight will have 8-10 LEDs. I'd suspect that an array of them (maybe 50) evenly spaced along the back of the box might work without further diffusion, but you may have to experiment if no one has tried it. Just take a small sample of the Lexan and 5-6 LEDs turned on (or a flashlight) and hold it behind.

[Don Nicholas]

Bill, I assume the sign is s/f, IMHO you would be better off using 800 ma T12 lamps for illumination. Using 4 lamps 60".
A rule of thumb comes into play, as far as the sign cab depth goes, usually figure, for even illumination, the lamps need to be spaced approx. 12 " on center and 1/2 the distance between centers of the lamps that distance should be the measurement to the back of the face to evenly light. Is the sign horizontal or vertical?
If it is vertical, think about putting a rubber washer on the bottom of the lamp to help to keep water out of the lamp socket.
IMHO I would forget LED'S in this application
Hope this. Helps

[Bill Maietta]

Thanks very much, Joe and Don. I really appreciate your input and the time to reply. I had very similar thoughts about this, but virtually no experience in this field to base them on. At this point, I'm going to propose a sign against the building. And, if he really wants to use LEDs run off a solar collector on the roof, then use those to light from above or from the side. I'm guessing even that would require a heck of a lot of LEDs.

Thanks again.

[Joe Pelonio]

The problem with that is getting enough light to hit the entire surface of the sign to make it readable in the dark. For LED use you would want to use a standard fixture with LED floodlight bulbs, probably 2 minimum, and the solar panel would have to generate 110 volts. Low voltage LEDs are just not enough light regardless of how many are used. The only alternative I can think of is to cut out the letters, and replace with slightly larger translucent acrylic letters, t5hen back light each letter with a bunch of low voltage LEDs arranged in the shape of each letter.