PR&NJRR posted:One thing I'm thinking of doing is setting up a weathering stand at the Somerset County 4H trainmasters June Show, and this year if they'll let me I'm thinking of doing Member's trains for a discounted price or free, and non-members for that price range I posted earlier. (Cars - $10-15, locos - $20-25)
I love weathering, and I say go for it, and wish you lots of luck! Bringing the models to life by weathering them brings a whole new dimention of fun to the hobby. But also do research on your models, use photo references. Be aware of the time period the model is in. Also Different climates effect rail cars in different ways. The cargo they haul can effect how the car looks (for example coal being top loaded into a hopper creates a lot of dust) steep mountain grades adds brake dust to the bottom of cars and trucks that may not be seen on cars traveling across flat ground. Gravity is also a huge factor, and should be reflected in your brush strokes (something I'm trying to perfect) Weathering is a big learning curve and I've just started really getting into it. I love some of my work and some of it is filled with mistakes. I don't use an airbrush. Just paint now but I did just buy some chalk. I put some photos of my models. Good luck!! 
