5'x12' sign install advice

[Blackhawk11]

Hello All - I am new to the forum with my 1st post. I am quoting a large (5' x 12') welcome sign for a town in my area. This will be in a high profile area, so it needs to look good and be durable. The design is simple, solid black background with raised white letters and white logo.

I really want to make the background seamless to eliminate any visible lines and failure points. The only materials that I can find as a single piece that size is either a 1/16" thick piece of aluminum or 15lb Corafoam HDU. I am strongly leaning to the HDU. The aluminum will still require an additional backer, have expansion/contraction issues, and be tougher for paint adhesion.

The good thing is that I already have a 2"x2" welded steel frame structure in place that was used for the old sign. That frame was welded to 4"x4" steel posts embedded in concrete, it is solid for sure.

My idea for attaching the HDU (1-1/2" thick) is to route dovetail shaped grooves 1/2" deep x 1-1/2" wide and glue in mating dovetailed MDO plywood strips. Then I can screw through the steel frame into the MDO without having any holes on the face of the sign (no patching). The dovetails would lock everything in place.

Is this method sound? Anything that I am overlooking?

 

[bannertime]

There is a company that makes 3mm 6x12 acm as a backer for channel letters. Here is a 5x12 version. Not sure if they have a location near you.

 

[visual800]

Id go with the aluminum, personally. It would be less expensive and more durable for the years to come. Paint the background with a nice quality latex paint after that cures out, silicone your lettering to it. Painting raw aluminum I use a 2 part automotive epoxy, scuff and then spray latex on top.

 

[Blackhawk11]

I've never used aluminum as a backer before. Do you take any steps to counteract the thermal expansion of the aluminum? This thing will be painted black so it will be a heat magnet with the sub beating down on it.

 

[visual800]

I've never used aluminum as a backer before. Do you take any steps to counteract the thermal expansion of the aluminum? This thing will be painted black so it will be a heat magnet with the sub beating down on it.

.063 aluminum is pretty stout if I was installing this I would use tap screws (pan head philips as opposed to hex head to be hidden better) and drill hole slightly larger than screws and put this up hot. Let it sit near the frame, get nice and warm and then put up. I would put 3 screws vertical and maybe 7 horizontal. You cant spot weld studs on rear of .063 you would damage material

I would scuff the rear where the steel frame was and do some silicone here and there where the aluminum is touching steel, you should be good to go. Never place silicone horizontal as it would trap water and rust the steel

 

[Notarealsignguy]

Wouldnt it be much easier to use black aluminum?

 

[visual800]

Wouldnt it be much easier to use black aluminum?

the longevity of stock black aluminum is not good. I woudlnt give black aluminum 2 years life in the deep south, painting is a necessity

 

[Texas_Signmaker]

the longevity of stock black aluminum is not good. I woudlnt give black aluminum 2 years life in the deep south, painting is a necessity

What happens to it? (Asking for a friend)

 

[Billct2]

Seams on a sign like this aren't usually objectionable and depending on the design can often be minimized behind the letters/logo. I'd use prefinished acm and add a nice raised border .

 

[visual800]

the stock colors on aluminum sheeting will oxidize in no time. Its a very thin layer of paint, I rarely use stock background colors on my signs unless temp or real estate signage