Taking the advice of several people, I worked on my train layout yesterday. I disassembled my L-shaped layout of two 4×8 tables, rearranged them to make an 8×8 area, and now put down a combination of Lionel and Marx wide-radius track.
As always, there was something to learn.I made an up-and-back-down loop with a modern K-Line 24-piece trestle. I think K-Line makes the best trestle on the market today and it’s the one to get, unless you happen to find a used Lionel or Marx one and can get it cheap. (Make sure all 24 pieces are there!) The K-Line trestle is intended to sit right under each track joint. Lionel and K-Line track ties actually sit right on the trestle. Marx ties are spaced just far enough apart that the trestle fits snugly in the gap. Neither arrangement causes a problem. You place the trestle piece, then drop two metal clips in place and screw them down tightly enough to hold it together.
But when you have a mixture of Marx and any other track, those track joints cause a problem. They’re too close together for the trestle to fit in between, but too far apart for them to sit securely. The problem is most pronounced on curves. So what I ended up doing was turning the trestle slightly to get more available area to hold the ties. It worked.
Another possible solution is to get out a slotted screwdriver and start prying up tabs and moving ties around. I opted to dink around with the trestle pieces instead.