WEATHERING WITH CHALKS

Lately I have been experimenting more with powders and chalks to weather rolling stock. Reading various reviews on chalks I see mixed reactions to the quality of the look that these materials produce. After applying the powders I am a convert. The only watch-out is to not overdo the amount being applied. However, if that does occur it is easy enough to apply other colors to reduce the area that was overdone. Here are a few examples...

The top "house" / box car, a laser wood kit by BTS, is painted the dark slate blue color known for the W&A. The walls have been altered as was the case on many lines. When troops were being hauled about, the lack of air flow caused the fellas to tear out the walls. There are some reports that entire cars were reduced to the frame.

First application is a gray tone for the basic fading. I may use two or three different tones. Last is the reddish brown. This simulates the GA red dirt.
I have found Doc Brown's weathering powders to work very well. He offers about 6 shades of brown and 6 primary-like colors.

I also use Prismacolor pastels. As you can see with Prisma, there are a wide variety of grays. In this grouping there is a dark color that nearly matches my dark slate blue, which is a Tamiya color called Field Blue. When I overdue a color I can hit it with colors close to the base color in order to soften the hue. The lighter grays give that additional weathered look of faded paint and wood versus using a pure white. 
Here's a few other cars weathered with these powders and chalks.