cleaning

[tonynz]

I know this issue arises all the time  ,would there be someone out there who can comeup with a result on blackening rail

I run DCC  ,2 tracks

[Medina1128]

If you have blackening rail, it sounds like you're using brass track. It turned black when it oxidizes. I'd suggest swapping it out for nickel silver. If you're already using nickel silver, then I'd say that your layout's in a dusty environment.