Bruce’s comment about mixing up the approach to weathering on different cars is quite valid. 

Way back in the early ‘80s there was a group best described as Friday Night Drifters in Denver. For one Friday I had painted and lettered a dozen or so Athearn blue-box 55-ton two bay hopper cars. Took them to the group along with a selection of chalks and turned them loose to “Practice” their skills. The result was that while all cars were of the same class of hopper car each now had a different degree of weathering and weathering pattern. White the weathering medium was the same for each car, the application varied from Drifter to Drifter. The results were quite acceptable. Also, in one fun evening I had a string of quite nice looking individually weathered cars. ;-)

Cheers,

Bill Keene

Irvine, CA