Was playing with some Atlas flex track last night, practicing soldering. This is new nickel silver stuff. 1. What kind of preparation should be done to the rail before soldering? On some of my practice joints, I filed the side and the bottom just a touch, on other practice joints, I didn't do any prep of the metal. Both held equally well as far as I could tell. 2. When making curves, which side of the flex track should be on the inside of the curve? One of the rails is pretty well attached to the ties, the other side is relatively free to slide along the ties. The side that slides freely also doesn't have as many plastic connections between ties as the other side does. I am assuming that the side that slides freely would be the inside of the curve? Or does it matter?