My question is do you think a 10' sheet of .040 aluminum mounted to a building will get wavy in the hot sun?
Yes, .040" will be wavy, even without hot sun. .063" would appear flatter, but still have some waves. I don't care for Alumalite for signs like this. I've seen it delaminate at the five-year mark and I consider it a semi-temporary material. I also don't like the way it dimples from fasteners. Incidentally, even many of the solid core ACMs we use are considered only five-year substrates (see the specs on Polymetal at the manufacturer's website, Nudo, Inc).
So, are these clients wanting a high quality-looking, long-lasting sign, or are they cheapskates? Or something in between?
My preference on a sign like this is to make a single piece pan in the shop. I don't brake the returns, but make the returns out of 1-1/2" or 2" angle in 20-foot lengths, attached to the back of the sign at top and bottom, plus two short pieces at the ends, mitering the corners. A vertical strip added behind each seam keeps the seams from opening. Built this way, a sign is solid and strong, and not that hard to install. To install, simply prehang a single piece of angle on the wall, level, to serve as a top cleat. Then lift the sign and hang it from the cleat. The cleat supports the weight while you install fasteners. If you use a cleat both at the top and at the bottom, you won't even need to fasten through the face. Just fasten through the top and bottom edges into the cleats. A sign built like this will look substantial and last a long time. And it will stay flat.
What to use for the face? When I had the equipment for it, I would use .080" welded to the angle aluminum back frame. I would punch 3/8" holes in the angle on 8 or 10-inch centers and put a small plug weld in each hole on the backside all around the perimeter. Yes, a lot of welds but it goes very quickly once you learn not to burn holes through the .080". I welded the corners as well. Install with a two-man bucket or a crane.
Or, for a lighter, less expensive version, easier to install, but that will still look flat and last a long time—
Face the angle frame with .063" instead of 080", attaching with pop rivets instead of plug welds. Again, an easy install with two ladders and a helper (not a child).
If you don't want to deadlift the sign as you climb the ladders, hang two "Rope-Ratchets" from upper rungs on each ladder, assuming your extension ladders are not lightweights and are long enough. Then, using the ratchets, pull the sign up from pick points attached on top of the frame near each end.
In my opinion, a back frame always makes a sign look better than just screwing thin panels to a wall, and it prevents waving and puckering.
Rope-Ratchets
I bought Rope-Ratchets when they first came out many, many years ago, sold as tie-downs. The heavier version Rope-Ratchet came with a length of 3/8" braided (not hollow) rope, which I replaced with long lengths of the same type rope and then used the ratchets for lifting. When I lettered wall jobs off of a pick-and-ladder setup, before I got a bucket truck, I could use the ratchets to raise my aluminum walk pick to near the top of two extended 32-foot ladders by myself. I would do this by hooking the ratchets to rungs near the top and then alternately pulling on each rope, raising each end of the pick 3 or 4 feet at a time till I got it up where I wanted it, then climb the ladders while the pick dangled and install the ladder jacks under it. After this I could release the tension of both ratchets and let the pick rest on the jacks. I never had the rope slip in the ratchets unless the rope was wet.
As might be expected, building a setup like this by myself was a lot of work. I felt like a superhero. But then I hired a helper and it was much easier.
Of course, pick-and-ladder scaffolding is illegal in many areas these days, so I wouldn't use it. I am no longer a superhero, anyway.
Brad in Kansas City
