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Building a Module: Deck

The first article discussed building the frame of my first module up to the point of installing a luan deck. For some flat venues the next step would be laying cork roadbed and track. However, on this module the track level was built up with two inches of pink insulating foam to allow the desired cuts and fills.

The first picture shows what is trying to be achieved. Two inches of foam below the track level to allow fills and additional foam above the track level for the cuts and hills.

Construction was complicated by adopting two recommendations from NVNTRAK Club members. First, several club members indicated track laid directly on the foam was easily damaged. For better structural support, luan was used as a sub-roadbed imbedded in the top of the foam. Second, exposed foam at the edges of the module is frequently damaged in handling. Luan strips were used to protect the exposed foam at the front and two ends of the module. The back is protected by the sky-board.

In building up to the desired track level, the first step was to cut a one-fourth inch by seven-eight inch grove on three sides of the module top for the reinforcement pieces. Two inches of pink insulating foam was glued to the luan deck using Elmer’s Nano Glue and weighted over night. The edge of the foam was carefully squared up and luan reinforcement added to the two ends. The top of the luan is exactly two inches above the deck level. The second picture shows progress to this point.

At this point it was discovered that insulating foam is not uniform in thickness, with variations across the width of at least one-quarter inch. This complicated the cutting of a grove for the sub-roadbed. A router and bridge arrangement had to be used to cut the grove so the top so the sub-roadbed would be flat at exactly two inches above the base. The sub-roadbed width was extend one-quarter inch beyond the edges of the cork roadbed. The sub-roadbed was glued to the foam and also to the end pieces, for extra support, as shown in the third picture.

The rest of the work to make the module “show ready” followed standard practices with only a few “lessons learned” you might find interesting:
  1. As recommended in one of the “How To” books, a thin layer of contact cement on the cork roadbed was tacky enough to hold the track in place but would still let the track be moved around to the right alignment.
  2. A dramel tool, with several different wire brushes, was good for fine work in shaping the foam—but requires continuous use of a vacuum at the work site to capture the fine dust that is produced. The contours of the hill in the first picture were cut this way.
  3. Lightweight Hydrocal light was tried—but it is too fast or I am too slow. In the end, All Purpose Joint Compound was used for the smoothing work. It has a long working time but can take up to two days to dry.