Weahering I agree. If you don't try, you'll never know. I'm sure you probably have some old car around that you can practice on. Here are a few pictures. I don't go into real heavy weathering, but I don't like squeaky clean cars either. How often do you see clean equipment on the rails. These were done using chalks for the black streaking down from the roof, and I will usually give a light dusting of "mud" along the lower part of the equipment with an air brush. When I am done I will over spray the cars or locomotives with dullcoat to seal the car. These were done over 20 years ago. It acrually only takes a few monutes to do one.