Precision Board is strong stuff, especially the 30 lb board, but it is not structural. There are plenty of ways to add structure to a sign but my favorite method is to weld up a steel frame and then laminate it into the sign layers with only the mounting points sticking out when we are done. Doing it this way means there are no screws to let go, and limited ways we can get corrosion. It also looks good.
The carousel sign I posted yesterday is to be mounted to a sculpted tree. Today’s task was to glue up the four layers of the carousel sign. The horse itself had been sliced into two layers to fit into inch and a half thick Precision Board. I also cut two other layers from 3/4″ thick board. One had slots cut into it to accommodate the 5/8″ steel rod frame and the last layer would serve as a backing to seal it all up. We would use the PB Bond-240 one part glue made by Coastal Enterprises. It is spread on the piece and then activated with a spritz of water. It expands slightly as it cures which means it squishes out a little on the edges. This is easily sanded (or with the die grinder) off when we prep our signs.
If you look at the next photo carefully you will notice lots of details. I measured each rod to go into the routed slots (measurements are noted in red felt pen) I then cut bars to length and placed them in the slots and tacked them up with the MIG welder. I then pulled out the assembly and welded it all permanently. The next task was to weld on the two mounting bars perpendicular to the frame. These would be poked through the backing and welded into my tree.
I then glued up each layer. I like to use deeply embedded screws to fasten things together as well as the glue. I know it is overkill to both glue and screw but it gives me peace of mind. We’ll fill in the screw holes with a little Abracadabra Sculpt epoxy just before paint begins.