In my experience, there are two sources of "gunk" on wheels. One, as posited in this thread is the oxidation of the metal track (and wheels!), while the other has nothing to do with the track, but instead with plastic wheels. If you were to take a sample of the gunk on the wheels, not that on the track, I think you would find a curious mix of compounds. To be sure, nickel or brass oxide would be there, and may be the actual binder that holds it all together, but there would be other elements too, derived from the dust from various sources. This dust comes from human skin (the most common source of house dust!) as well as all those materials and processes we use to make our layouts. Plaster dust (short lived until it meets di-hydrogen monoxide), sawdust, plastic dust (from that kitbash project) etc, etc. These microscopic dust particles are attracted to electrostatic charges. The key here is static. Active electricity does not attract this dust, but static electricity does. Since metal wheels on metal track are all conductive, there is no static charge developed here. Plastic wheels, however, can develop a static charge, albeit small, that is enough to pick up those micron dust particles from the roadbed and place them at the point of highest charge, the contact point of plastic to metal. To be sure, when running a mix of metal and plastic wheeled cars, the majority of gunk develops on the plastic wheels first, then apparently migrates to the metal wheels.
I believe this to be true, although I don't have the government grant and ensuing research to prove it. On a previous club layout, we started with a mix of metal and plastic wheels. Dirt (track gunk) was a constant problem. Cleaning was required once a month if there was any significant operation. The club then mandated that all equipment operated on the layout must have metal wheels. Plastic wheels were verboten! Tadaaa! Dirt on wheels and track was practically eliminated! Occasionally someone would sneak in to the layout and run their plastic wheeled cars. We always knew. The track suddenly needed cleaning for no apparent reason. Now, I agree, and believe that the oxidation of nickel from the rail (and wheels) may be a major source of that specific form of gunk, I believe that plastic wheels bring in a whole new dynamic. Darrell Smith --- In [email protected], "johnalbee03@..." <johnalbee03@...> wrote: > > Fascinating. When I ran my finger down a new stick of flex, I got "black". > Oxidation? > You're saying, if I understand it, the metal wheels contacting the track, > cause arcing (sp) which pits the track? > Then, please "splain" why ya get gunk with plastic wheels. Really curious, > thanks > ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/S-Scale/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/S-Scale/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
