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Reinforce- ment I added strips of fiber- glass screen to the Satin mixture to make the structure stronger. Sev- eral coats were poured to complete the casting.


(old), and were on tangent track. I had to build the tunnels on a broad curve and shorten them to 178 feet and 138 feet to fit them on my model railroad.


Although I have been a model railroader for 60 years, none of my layouts ever progressed far enough to require scenery, so I had a lot to learn. The major chal- lenge facing me at Oscawana was construction of the curved tunnel liners with semi-circular roofs and perpendicular sides. The tunnel liners had to be continu-


ous since the tunnels are short enough to allow a viewer to see right through them. I researched the hobby press and found many articles on casting small parts with various resins and rubber molds. To make a casting as large as a tunnel liner required differ- ent procedures.


I decided to make a tunnel liner pattern to match what I needed and cast the part direct- ly onto the master pattern with- out a rubber mold. The basis for my pattern was a piece of four-


inch outside diameter PVC pipe that I cut in half on my table saw. I made a plywood pattern of the footprint of the tunnel using my track as a guide. I measured the length of the footprint pattern on both sides and determined that the inside length was 4½ inches less than the outside length. Since the width of my table saw blade is 1/8-inch, I made 36 kerf cuts about three-quarters through the PVC pipe. I bent the pipe to match the footprint pattern and screwed it in place with No. 4 screws. I


Base The lower third of the tunnel liner was made from styrene strip. This strip formed the vertical wall sections of the tun- nel liner.


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