What kind of tracks,one piece or indie links?
With one piece,you CAN use super glue,the newer Tamiya or Dragon one piece can use liquid glues like Tamiya or Testors,but BEFORE painting is best.
From the way your question sounds,I don't think you are talking plastic indies,but that's a whole other discussion,those are assembled with liquid cement also,usually before painting.Here's who I handle plastic indies.