Isolating a section of already-ballasted track?

[Puddlejumper]

If you have a dremel, it works really well. Just hold it steady, and work slow and easy. Works like a champ to cut gaps in track that is already in place on the layout.

If you expect your track to expand during summer, then you can plug the gap with some styrene, but if expansion is not a problem the gap will likely be ok as is.

Dave