Weathering Techniques for Realistic Results
Garden Railways 2008-08 pg. 70 Scale: G Category: "Painting & Weathering"
The author shows various techniques for weathering a tank car, a covered hopper, a boxcar, and a flat car. Specifically of interest is the effective rust streaks, which are covered in a step-by-step photo montage. The flat car has the plastic boards look like old wooden boards.