Gargraves track

I ballast and rust-paint the rail sides.

Weather it with a spray can or airbrush preferably before you ballast.  It does look so much better.

Dave

You can use Camo Brown from Krylon if you want spray cans, very flat finish. I mix my own color for air brushing, with Floquil Rail Brown, RR Tie Brown, and a little Rust. Mostly RR Tie Brown to eliminate the greenish toneof Rail Brown.

If you spray the track before installing it, the spray can (another vote for Krylon Camo brown) is quick and easy.

If the track is already in place on the layout, the controlled spray from an airbrush or brush painting (any dark brown) is preferable. 

Jim

I agree, air brushing would be the best way to go, you have much better control with the brush and way less overspray.

Another thought, you could also use the Woodland Scenics color pens, they have them in track colors, I've used them on some Sn3 track that I had been working on and the results were very pleasing.  Just a thought.

I don't have an airbrush anymore and use a sable brush with sash cut to paint the rails before ballasting--slow and labor-intensive but I am obsolete anyway. After ballasting clean rails of paint and glue mix but haven't done so yet--trains don't run.

I use Tamiya XF-64 Red Brown Paint.