Dirty, dirty hoppers

As my roster of hoppers grows I decided I had better get cracking on weathering. I have been experimenting with different techniques. I read a great tutorial by Tom Mann and here is what happened when I mixed some of his ideas with some of mine...Not all my hoppers will end up in this condition, but you need to have some that show the wear and tear of time. This hopper I received from my friend HK, I put MT trucks and BLMA wheels on it. The car and trucks got a diluted spray of Roof Brown and a light application of burnt sienna for the rust. On the wheels I used a micro brush to paint the sides roof brown.