Construction: laying track

Finally I get to lay some track!  The distilled wisdom of the Internet has told me that nailing is bad, gluing is better, and gluing with caulking is the best. Transparent caulk is what I see recommended most often (so it's not unsightly if it peeks through the ballast), but I noticed some nice gray caulk at Rona (again, same DAP Alex+ brand) for the same price as the clear/white/almond/brown colours. I don't know what they put in it, but I found that the 300mL tubes of white-becomes-translucent and gray caulking are significantly different in weight. Indeed, the scale reveals: clear = 350g (12.3oz) whereas gray = 469g (16.5oz). I assume the differing ingredients make the gray caulking that much nicer to spread. For laying track I run a bead up each cork half-strip (approximately under where each rail will go) and then with a cheap putty knife spread it out into a smooth thin layer (1mm [~1/32"] is all you need). Just like icing a cake. Once the caulking is spread out thin and smooth, just plop the track on top if it and press down gently. The caulk is sufficiently sticky to keep the track in place with minimal clamping.

Backing up a bit; before getting to the sticking-it-down part, I first lay out 3-4 sections of flextrack at a time along the roadbed, pinned and/or clamped in place temporarily, then cut the rail ends as needed to fit the curves. Once satisfied with the alignment, I solder the rail ends together, but I don't solder in the curve -- I clamp the the end of the first track a few inches back from the end and let it straighten naturally, then attach the next section of track tangent to the end. This way both rail joints will be soldered perfectly straight and can then be bent into the curve. Attempting to solder in a curve is a great way to get kinked joints.

My soldering technique is far from perfect (as is my equipment), but what I do is clamp some alligator clips to the rail on either side of the joint as a heatsink, then apply the iron to rail+joiner on the outside of the rail and melt a small bit of rosin-core solder into the space between the rail joiner and the base of the rail. As soon as that melts, I take off the iron and blow it cool (to avoid melting ties). Then repeat on the other half of the joint. Once both rails are tinned, a third application of the iron blends the solder across the joint (if it wasn't already) and smooths out the appearance.  I only solder on the outside of the joint to avoid any potential bumps and lumps where the wheels will roll.

At the end of the first day of tracklaying I have 33 feet of mainline down, from the yard, around the base of Marshall Hill and almost leading into the curve on the outside of the second level of the helix.