The hollow-core door I selected was selected for its availability rather than its dimension, as it was part of a cash and carry sale at a local salvage shop. Although the hole for the doorknob had been drilled through it, the door was structurally sound ‘ certainly sufficient for my needs. Despite that, I added some framing on the underside to allow for wiring, turnout controls etc. The advantages of now having a void in which to run wires were complimented by having some extra material to attach the future facia as well as the control panel.
I cut some 2x2s out old 2x4s I had in the house on the table saw and attached them around the perimeter of the underside of the door. If not for the 2×4’s, I would have simply purchased some 1×2 pine, or 2×2 spruce strapping. I didn’t bother to mitre the corners, and glued and screwed the lumber into the solid edges of the door. I cut some extra lumber so that I could add some cross braces after I had installed the track and the wires. I laid the door flat on the floor and added some weight around the edges to prevent the off chance of the door warping while the glue dried.
Once the glue was dry, I turned the door back over and removed the Kraft paper on which my ever precious track plan was doodled. As I imagined at least one river on this pike, I attached some 2″ Styrofoam to the entire tabletop. The 2″ foam allows me to make changes in elevation with a steak knife (2 inches of foam translates in 26 scale feet of ground) rather than a reciprocating saw, and gives the model some added rigidity. I had fully intended to use extruded pink/blue foam, however, when I was price shopping at my DIY centre and explained my project to the attendant, he offered me a cast-off sheet of 2″ 4×8’ white bead foam for two dollars. I didn’t argue with my good fortune. The piece of foam he gave me was for exterior use, and as such was somewhat water-proofed, containing smaller beads than the standard foam. Because of this, the foam doesn’t ‘shatter’ into snow-white shrapnel like its cruder counterpart.
I attached the foam to the tabletop using regular carpenter’s glue ‘ I didn’t have any other adhesives suitable for foam. (Solvent-based glues will eat through the foam like a hot knife, giving little or no bond, and leaving you with something that looks like termites ate through it.) Again, I added some weight and gave the whole structure a few days to dry.
Once the glue was set, the combination of the bracing and the foam resulted in a very rigid footprint.
