Sorry I did not reply sooner, but I was at the “Mid-America 3-Railers” meet and at then at the wonderful picnic for the group at Alan’s (leavingtracks) house this weekend.
Lou -
I use 1/2" thick pink insulation board for the walls that resemble cut rocks, as the ones with arches around the subway mall, and also for several tunnel portals. I use 1" thick for walls that resemble poured concrete walls.
I tried many different methods for cutting and 'scribing' the pink foam board, and have settled on mainly two methods. For straight cuts of the 1/2" thick board, I use an X-Acto No. 26 blade and a straight edge. For cutting the 1" thick board, I use my band saw. The 1" thick board can be cut with the knife as well, but it is a bit tricky to maintain the cut at right angle throughout; but it can be done.
For cutting curves I use a hot wire and a template made of 1/4" masonite, but plywood or any other hard material would work fine for the template.
After the foam is cut to size, I paint it with latex wall paint that I buy at Home Depot in sample-size containers (about 8 oz) for under $3, and they will mix any color you want. (The foam can't be sprayed because enamels will dissolve it.)
After the wall is painted, I use a pencil to scribe the rock and poured form lines. For rocks, I use a slightly blunt pencil; and for poured concrete forms a slightly sharper pencil. I make my rocks 1/2" x 1" (2' x 4' full scale), and the concrete forms 1" x 2" to simulate a 4' x 8' sheet of plywood as may be used in real.
The poured walls also have an upper ledge and vertical reinforcements that are strips of foam 1/4" to 1/2" thick and 1" wide. I glue these to the wall with hot melt glue.
Here is an example of a tunnel entrance I am about ready to install. (click to enlarge)
Leandro -
Thank you - I'll continue to post as I progress.
Alex
PS. I forgot: For the tunnel portals - before painting them, I hit (softly) the wall surfaces with the ball end of a ball peen hammer.
