Assembling and mounting the Flutterbye sign proved to be easier than designing it. When we built the control booth and tree we left one piece of structural steel about 24" long. The slot I designed into the middle piece of the Flutterbye sign fit right over this piece of steel. I positioned the center piece of the sign over the back piece and glued and screwed the two pieces together using PB Bond 240 (one part) glue. We then hoisted this piece of the sign into position.
I then spread the same glue on the back of the sign face, spritzed some water onto it (to activate it) and aligned it with the back pieces and then screwed them together. The glue in the slot will expand and fasten the sign permanently to the structural steel. We'll let it dry until tomorrow. Then I'll use my die grinder to even out the sides, top and bottom of the sign and add some subtle texture to the back as well. Once the screw holes are filled with the little sculpting epoxy it will be ready for paint.