A few weeks ago we had a project to build a pole sign, all metal construction, in two units, with all radius corners. While there might be any number of ways to construct a non-electrical sign like this, I knew I would do a lot of the work myself, and it would be made of mostly pre-finished aluminum. If I could do it without welding at all, there would be no need prep, paint or powder coat. The factory finish on the aluminum could stay masked and unmarked, ready to install.
Really, at least with the wire-fed gun we have, I am not proficient at aluminum welding. But, I have done a lot of sheet metal work, and have a 10’ break and some CNC equipment at my disposal. This sign would be riveted together, formed around geometric parts cut on a waterjet or router, formed basically by hand and with a brake, and built light enough to allow installation using my bucket with lift. No crane needed.
I can’t say it went together as fast as I imagined it would in my mind, but there were no real problems, and the result was as good as I could expect. While there were several hundred rivets, no welding was needed and the sign was plenty strong. It would mount over an existing pole, and a steel extension to the existing sign pole was the only welded item on the job.
First, of course, there was a good bit of time designing the parts. Then it took an afternoon or so to cut all the pieces on a waterjet available at our other shop, WPC Services. On all the main pieces, small tabs were placed all around the edges, bent upward 90 degrees, and curved formers were riveted to these tabs to give the signs their shape.
The top sign was a large circle about 54” in diameter and 16” thick. And the lower sign was approximately 3’ x 9’, with 8” radius corners, and the same thickness. Originally I had drawn the rectangular sign with 6” radius corners, following a design our client’s advertising agency had drawn up. But, I was determined to make all the parts in-house, with no painting or finishing, so the trim pieces or retainers would be made from silver anodized .040 aluminum would have to be formed to the radius corners of the sign. Through some experimentation early on, I determined this type of shop-made trim could be curved to a radius no smaller than 8” before it would kink when hand forming, so that was the radius we went with.
All of the sign parts except for the silver trim pieces were made from pre-finished .063 white aluminum sheets. No frame was made of anything other than that, so both signs involved were basically sheet metal creations.
The top sign, a simple circle shape, was made from two strips with tabs around the edges bent on a brake to 90 degrees, and the two pieces joined at the exact top and bottom quadrant of the circle. For each side of the sign, there were four radius formers of a quarter circle each that defined the shape of the circle. At the very last I made two “stringers” or stiffeners made of 1” x 1” aluminum tubing. These were put in at 90 degrees from each other to hold the circle shape exactly the same diameter north-south, and east-west.
There were special parts designed for the exact top and bottom of the circle. The bottom joining piece re-enforced a circular cutout to accommodate the pipe that would come a few inches up through the bottom of the sign. Inside the sign, a steel tube extension was to be welded to the top of the existing pipe sign pole we were mounting the signs to, and that tube would fit a socket inside the sign at the top. The socket fit fairly loose, but there was a “bushing” made that fit the square tubing mast snuggly and the position of that bushing could be adjusted slightly to level the sign perfectly. The bushing would be attached with large rivets in place on the socket, locking the sign in place.
The lower sign, as the photos show, was put together by adjoining four main strips of sheet metal, again with 90 degree tabs all along the edges. Riveting these tabs to formers made from the same white .063 aluminum. Joining pieces at the top and bottom center provided cutouts for the sign pole to pass through. A ring of 1/8” steel was welded to the pipe in the field where the bottom of the sign was to stop and the sign would bolt to it. There were a couple of sheet metal pieces made to form an adjustable bushing at the top of the lower sign to lock it snuggly to the sign pole.
The actual sign faces weren’t made until the sign structures were completely fabricated, and the exact shape and dimensions were confirmed. The round faces of the top sign were made from aluminum laminate covered with a digitally printed graphic, and the lower 3ft x 9ft faces were made from more pre-finished aluminum sheet, covered with a reverse graphic of blue hp vinyl. The cracks or seams at the edges of the faces had to be kept small since the satin silver aluminum retainer strips would have a very narrow lip of just aboutr 5/16”, only enough to hide the seam and the small rivets that actually held the faces in place before the trim was installed.
The signs would be installed without faces in place. To make sure the 9’ long lower sign did not sag in the slightest amount and the faces would fit right back into pre-drilled rivet holes, a pair of formed aluminum “purlins” were installed on each side, making the sign even more rigid. These were screwed to vertical members made from light wall 1” x 1” aluminum tubing. Later, after the sign was in place on the sign pole and the faces were put back in place, each rivet hole lined up perfectly.
Except for the top mast added to an existing sign pole, as intended, there was no other welding required on this job. But with all that drilling and riveting, the project seemed a little like putting an airplane together. One real similarity was the use of “clecos” as temporary rivets when fitting something together. These spring loaded re-usable fasteners are most often used in aircraft construction, but can come handy for sign making as well. And at less than $1 each (from Aircraft Spruce and Specialty) they are inexpensive enough to keep a set of them to fit 1/8” holes, and 3/16” holes for standard aluminum rivets.
The final components of this job were the shop-made retainer trim pieces that trimmed out both sign units nicely. Strips of satin silver anodized aluminum, .040 thickness, were cut on a shear about 1?” wide and 4’ long. Each piece was formed on a brake, bending up an edge that was 5/16” wide, and of course these pieces were perfectly straight. But these pieces were formed to the correct radius for both the upper round sign (slight curving radius of about 27”), and the lower sign with corner trim that had an 8” radius. They were hand formed carefully over a scrap piece of plywood cut in a rounded shape that was clamped to the edge of a work table. This part of the job took about a half hour to complete, making plenty of extra retainer pieces just in case.
The retainer pieces were not installed at the shop at all, but were installed around the perimeter of both signs only after they were up and faces in place. Final trimming to length was done in the field quite carefully using a decent pair of tin snips.
All in all, it was a fun job and the final results more than satisfied everyone at our client’s new office location. No painting or powder coating was done, since all exposed surfaces were pre-finished aluminum, and the clear masking was kept in place until the signs were up.
My nephew Jeremy and I rode the signs up in our shop’s manlift, but neither sign weighed more than 75 pounds, the top sign weighing less than half that. The signs were lowered down over the existing sign pole to which we had added our pole extension earlier.
As mentioned, each sign was tightly secured at its bottom, and had an adjustable bushing at the top, making it very easy to get the signs exactly level and permanently in place with no welding required. Which was just what we wanted, and the signs turned out just the way the client wanted. And, a satisfied customer, of course, is the only kind to have.