Originally Posted by Hot Water:
In my opinion, the biggest mistake that a lot of folks make when it comes to weathering steam locomotive running gear (rods) is, they are not really knowledgeable about what actually adheres to the rods/running gear. The forward portions of the running gear get the steam oil and machine oil thrown off the piston rod and crosshead guides, which tends to be pretty sticky stuff, even when hot. From the middle portion to the rear portions, the running gear picks up the white sand from the sander discharge nozzles, thus the wheels and rods pick up a very light color, getting heavier towards the rear.
I agree fully with this. You only have to google shots of rods and valve gear of operating steam locomotive to see this.
