Weathering Rails ...

[AirbrushNo5]

I had to do some touch up painting here and there… tone down some whitish areas from IPA or white glue…
No big deal

 

[Slate Fork]

So, help me out here:

You paint your rails,
You paint your ties,
You lay your ballast..

…If you set your ballast with one of those glue (or matte medium) in water & isopropyl alcohol mixes, does that negatively affect your painted rails and ties?

No, it won't.

 

[CambriaArea51]

I don't use alcohol. A couple of drops of dish soap in the water in the spray bottle to break the surface tension. The 50/50 Elmers and water and drip it out of the bottle onto the ballast.