Any metallurgists out there? I know there are many threads and posts on track cleaning, but I'm hoping for a few comments on tarnish from anyone not minding repeating himself (or herself).
I have a medium-sized N-scale mountain division layout with PECO track and medium turnouts. Max grade is just under 3.0% (prototype is 3.6%), curves are minimum 16 inch radius and are super-elevated. I'm a neat freak, so dust doesn't collect on the track. What DOES affect operation, I've noticed, is tarnish. The track and turnouts LOOK clean, but running a finger or cloth over the rails shows - I assume - black tarnish. I notice that if I run trains every day or couple of days, the track seems to stay cleaner than if inactive. If I go 2-3 weeks without running trains (or cleaning track), headlights begin to flicker slightly as thought the track is getting dirty. Cleaning track and turnout points corrects the problem immediately.
So here's my main question: does running trains have a cleaning action where wheels remove tarnish? If so, how long can you not run trains and still have track remain "clean" - i.e., no 'hidden' tarnish?
A couple related questions:
Does running trains promote or decrease tarnish on wheels?
Do you find that your super-elevated curves promote tarnish on the low rail?
I've read about and tried all liquid cleaners. Mineral spirits seemed to work best for me, but I think even it leaves residue - using it seemed to flicker the headlights sooner than if I used dry means of cleaning. What's been your experience using wet versus dry means?
Here's a tip I offer - something I just observed on one curve that was causing headlights of Minitrix F9s to flicker (poor electrical contact). Grab your track gauge and check the track. Even if you're in a temperature-controlled room, slight changes in temp may cause your track to move. If a rail can't move fore-and-aft, it will try to move side-to-side, changing your track gauge. I corrected my problen by sanding the insides of the rail heads - slightly - with an emory board.
Happy Holidays to all!