Shop Talk: The Basic Swing

A swinging sign is a simple project, but dangerous if not built to last and last. Here’s a good way to construct a durable, safe swinging sign. (Right) The hanging bars or mounts for this sign are made of 1/8” x 1” steel flat bar, but the ends prone to wear are beefed up by welding thick lock washers as reinforcing.

From time to time we are asked to build a sign that swings, and when we have to make this type of sign, even if it’s just a simple project, we want to make it last. The last thing we need to build is a falling sign.

There are several ways to built a swinging sign, and different types of hardware that can be used for mounting. The type of sign we’ll look at here is very simple, but extremely durable and safe. The mounts it hangs from are integral parts of the sign itself and they are not going to come out or wear out.

The photos show the sign hanging from a chain, but that was just for getting a finished photo of the project. It was shipped to a distant customer, and they did the installation on site, which we have not seen. Our concern was the integrity of the sign, its safety and longevity.

The “eyes” are drilled out on the reinforced mounts. After welding and drilling, the mounts have their ends rounded plus the welds and rust cleaned with a hand grinder. Two 1/2” MDO faces will be used back-to-back, and are cut to match each other by clamping together and trimming to shape with a hand jigsaw.

The edges are rounded over with a router. This isn’t just an aesthetic step; the edges will shed water readily after rounding, greatly improving the durability and longevity of the paint job and the sign itself. A groove wide and deep enough to accept the flat bar mounts is cut into one of the faces. The mounts are screwed into the ungrooved face, positioned to mate into the grooves on the back of the matching face. Short but strong #12 wood screws are used to secure the mounts to the 1/2” thick panel.

A LONG AND SAFE LIFE

To guarantee its long and safe life, the main item of concern was the mounts incorporated into the sign that it would swing from. These were made from flat bar or steel strap, 1/8'' thick and 1'' wide by the height of the sign plus two or three inches. We had to keep these mounts somewhat thin because of how they would be sandwiched into the sign, but to reinforce the areas that would be subject to wear, we welded washers to the top ends.

This reinforcing made them much more capable of handling many years of wear. After welding, the straps were drilled out on a drill press, and then rounded off and cleaned up with a hand grinder.

Primer is applied to the back sides of the faces and allowed to dry before they are secured back-to-back. A wide, thick bead of 25-year caulk is applied around the grooved panels edges, and generously into the grooves where the mounts will fit. This will make a very water resistant seal between the two panels.

IT’S MADE OF...

The sign was made of two 1/2'' thick MDO panels laminated together. They were clamped back-to-back and cut at the same time to ensure a matched pair of sign faces. 

The edges of each face were rounded off using a router and a 1/2'' round-over bit. The faces could have been just sanded around the edges, but making the edges round actually serves an important function of shedding water easily. Rain water allowed to stand on the edge of any wooden sign will find a way to penetrate and begin its destructive work. If the water isn’t allowed to stand, this process takes much, much longer.

Several clamps are used to squeeze the faces together, and slightly counter-sunk wood screws, which will be filled and painted over, make the bond permanent.

At this point, the signs were separated and one panel was marked where the strap mounts would go, and then grooved or recessed with a router following a clamped-on guide of angle iron. The steel flat bar mounts would fit flush into these 1/8'' deep grooves.

PUTTING IT TOGETHER

On the opposite face, which was ungrooved, the flat bar mounts were accurately secured so they would fit into the grooves in the matching face. Using several short #12 wood screws in each strap, the mounts were secured in place. Having no groove in the second face meant that it was thick enough to receive the wood screws, whereas if both faces had been grooved, the screws would not have been able to get as good a bite.

The two faces were then primed on the sides that would be on the inside of the sign with fast drying block-out white primer. When the paint was dry, a good bead of 25-year latex caulk was applied to the face with the grooves, and extra was put into the grooves themselves. The faces were clamped together tightly, squeezing the excess caulk to the outside and making a gasket-like seal. A border of slightly countersunk wood screws was placed all around the outside edge of one sign face. These depressions would be filled and sanded smooth later.

After filling and priming the exterior sides of the sign, a bit of sanding is done before applying the final coat or two of enamel. Sign background enamel is applied with a foam roller on one side, with the sign supported up off the table on paint cups to allow painting the edges as well.

Once the finish is fully dried, the hp vinyl graphics are applied. With permission, the customer’s logo was tweaked a bit so it would fit a symetrical shape. The mount extending out of the sign, goes through the sign nearly to its bottom edge. Unless this sign totally deteriorates, it will not be coming out or even wearing out at its eye.

THE FINISHING TOUCH

The excess caulk was scraped off with a squeegee. Screw depressions and any other scratches were filled with Bondo, and when it hardened, the faces and the sign edges were sanded smooth and the whole sign was given a coat of primer.

The final paint job was done with a foam roller, one side one day and the other side the next day. Then the vinyl graphics were applied using hp black vinyl. The customer’s logo, with permission, had been tweaked a bit and the shape of the sign had been made so that the design would fit symetrically on either side.

The finished sign will last for years and can not become unsafe unless the whole sign deteriorates because of old age. The rounded edges of the sign will shed water (very important), it is sealed virtually water proof, and the mounts are imbedded into the sign permanently. Also, the weight of the sign, actually two faces back-to-back, makes it heavy enough to not swing excessively. Though the construction of the sign was simple, this basic kind of swinging sign has the durability, safety and longevity required in this type of sign project.