clear lexan over aluminum sign

[signgal01]

I have a sign project that the local city council, county commissioners and numerous other committees didn't want just a laminated printed graphics on aluminum in a metal frame. So they asked for a clear Lexan sheet on top of the aluminum panel with graphics. Here is my question, would your sandwich the two pieces (aluminum and clear lexan) and seal the edges with calk before putting in steel frame or leave the two pieces in the frame loose? My worry is condensation of moisture between the two pieces.

Thanks, Vicki

 

[ddarlak]

I wouldn't worry about the condensation as much as the softness of the Lexan and how easily it will get scratched. I'm assuming in their infinite wisdom this is an effort to make the sign more vandal proof. Acrylite would be better suited in this application IMHO

 

[Billct2]

Yep, what's the point? To make a "vandal proof" sign? If the purpose of the lexan is to protect the sign there are always issues with how to make it work.
Condensation, dirt, insects can all get between the two faces. I have found that the best option it to leave a wide gap using some kind of stand offs.

 

[IslandSignWorks]

The sealant will eventually crack and fail and you will get moisture inside, mold, maybe bugs, etc. Aluminum and acrylic expand and contract at different rates, so the chance that these two layers are going to stay together forever is pretty slim.

If graffiti is the concern, there are some anti-graffiti overlams on the market that make it easier to remove spray paint, marker, etc. OL-1000 Premium Anti-Graffiti | Avery Dennison | Reflectives

If straight up vandalism is the concern, there's not much you can do about that.