black ring vinyl liner

I'm guessing it's some kind of staining from environmental factors like pollution. Here around Chicago we get it too, but the Eraser usually takes care of it... I asked about the ionizer systems because the copper can leave a ring too.
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.