I was quite pleased six or so months ago to hear on this forum about Simple Green cleaner. Nothing I have found before of since cleans my track of gunk and whatever impedes electrical connectivity as effectively and fast. Amazing . . .
EXCEPT - every time I use it now, within just two days -- as predictably as swallows returng to Capistrano, the track is really "dirty" again, covered with a nearly electrically impermeable dull, grayish gunk that feels a tiny bit sticky and plastic -- but I can definitely feel it with my fingertips. . . and my trains just won't run well at all.
This gunk comes right off with a pad moistened with Simple Green. One swipe and its gone . . . but returns within a day or two, just as bad or worse than ever. . . This happens if I use the Simple Green on a pad by hand or if I use it in my track cleaning cars - either way.
When I switched back to isoprophyl alcohol this problem went away. My track still gets dirty again -but in a way that it always has - slowly and with a darker black kind of tarnish . . .
Of course, with alcohol, cleaning normal gunk and grim off the track is noticeably more and slower work than with Simple Green (it really is amazingly instant in cleaning!). But . . . no side effects!
My operating theory - it explains everything but I can't prove or disprove it -- is that Simple Green is interacting with the plastic Fastrack roadbed. That repeated use "weakened" or softened the Fastrack plastic surface so that now each repeated application creates gasing or quickly gets a residue from the softened plastic on the cleaning pad and transferring some plastic residue to the rails, where in a day or two it hardens. Regardless, it was a lot of work (all by hand) to remove this simple Green or whatever it is residue from my Fastrack rails using only alcohol. I also found I had to use a whole roll of paper towels for only about 300 feet of track as the towels were noticeble "gunky" after only a bit of cleaning - I guess they were picking up and absorbing that gunk, whatever it was. But it was worth it, because the residue has not come back since and it has been over two weeks.
Anyway, much as I loved the stuff, I poured the rest of mine down the drain and will stick with alcohol for track cleaning on fastrack.