I had a bit of code 55 weathered on hand so I decided to use it to build switches. Clean the bottom real well and solder away. Sounded great. The problem I encountered was conducting the heat from the iron thru the top of the rail base to completely liquefy the solder to get the optimal bond across the base of the rail on top of the ties. That coating kills the heat transfer. I only tried it once so perhaps I screwed up somehow?