Brother Bob,

Me I like a very dirty weathered look. Not so much for when you are looking at in person but when it is photographed. I had the chance to work on the models for a motion picture that many people might have seen and when I looked at the models they were an absolute filthy mess. But when the film rolls that grime and dirt made them look great.

I always start with a filter of dark brown. Now here is what to do if you go with a solid panzer gray. Once you base coat is applied mix some flesh color into the panzer gray. Just enough to change the hue slightly. Then turn the air brush way down and shoot to model on the high areas. This will give a somewhat worn look and give the eye something interesting to do. Then go in with a filter. Blot at it in random areas. Now lock it down with a matte coat or a dull coat. Then a heavier wash on the lines and areas around bolts, nuts..etc. Now a bit of soot in the exhaust area. Some dirt on the engine covers. Then a light wash. Then dry brush to bring out the details. Now a final dull coat.

Hope this helps!

Don