MIXEDTRAFFRIC.NET
How We Successfully Joined Track Across Module Interfaces
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This article is an 'how to" article that looks at a problem faced by all those who would build an exhibition layout: rail joints at module interfaces. It could also be used by those who want a modular structure but do not want to exhibit too, of course. It is particularly difficult to assemble modules and fit track together at their interfaces at the same time - even with infinite care some damage is possible. One answer is that you don't put a piece of track across the gap. This is what we have decided to do. The solution is 'fiddly' (but not difficult) to do, but is time consuming. This system works because the gap between modules is only (effectively) the thickness of the tool that cut the gap - grinding disk, saw blade, shears or whatever. A locomotive will cross this gap with ease provided that both sides of the track (i.e. both modules) have 12volt power to them. This is how we did it. (We also found that the more joints that you do the quicker and easier it becomes.)
Requirements: 60/40 solder; strips of copper clad PCB (printed circuit board) about 10mm wide; thin (2-3mm) wood also 10mm wide; icy-pole sticks are ideal) a hot glue gun and hot glue.
Method: Lay a length of track across the join (interface) area of 2 modules. 2. Mark the track where the cut will be made and remove the sleepers - we removed 3. 3. On the underside of the track where the sleeper-less gap is, tin (thinly) the underside of both rails with solder. 4. Put the track back in position over the module join and pin lightly into position. 5. Slide 2 pieces of the packing wood into position under the track - one on each module edge on either side of the proposed (and eventual) track cut. 6. Pin these packers into position. 7. Cut 2 pieces of PCB strip the same size as the packing wood. 8. Cut a groove in the copper of the PCB right through to the underlay parallel with the rails. If you don't do this it will short out your + and - rails. 9 Run a line of solder roughly where the track will be on the PCB strip, so that you can later solder the track to the copper face beneath it. 10. Put hot glue on the packing wood and slide the PCB strip (copper side up) between the underside of the rail and the packing piece until they are level on top of each other. 11. Hold the rail down on the packing/PCB until the glue has set, ensuring that the track is flat. Try not to let hot glue spread downward into the module interface. 12. Repeat this process for the other module. 13. Run a line of solder along the track so that the track is soldered to the copper face of the PCB. Do not apply too much heat or you will melt the sleepers. 14. When this is done and both sides of the joint are correct, cut through the track at the module interface. The track should not move (even though there are no sleepers under it) because it is soldered down right at the module interface.

Why is this a good method for both exhibitions and other layouts?
If you get to an exhibition and the floor is not level enough to get your intra-module track levels dead right (and they need to be if you don't want derailments) you can gain some minor adjustment by melting the hot glue with a soldering iron and either pushing the offending track down or lifting it slightly. This is obviously also true for your own layout room floor if (as mine is) it is not quite level.
(Peter wrote the text, Tony took the photos and Mike did the work.)
Copyright © Peter Baddlely & Tony Knight 2005