The itch to make some of my cars look a little more realistic-which in the case of anything with BN reporting marks would mean older-is what I've been trying to scratch. In the past the effort has involved spray cans, airbrushes, and sandpaper. None have been completely satisfactory, and especially in the case of airbrushes, the need for a place to paint and the clean up time are stumbling blocks to getting anything done. Recently the efforts have been influenced by advice like this.
So I've gathered up a small supply of tools and material, for example, this stuff:
And then I go to work as shown in the link to Jeremy's Dry Brush Technique, above.
Once I have completed the fade and sealed it with dullcoat, I bust out the Pan Pastel powders and a small brush to start dirtying up the car. If you try this, go easy, the powders are powerful strong, much more so than any weathering powders I have used. While my skills are far from perfected, I am somewhat pleased that the cars aren't ruined. At least I'm still willing to leave them in sight on my layout.
One of the challenges of weathering, for me at least, is knowing when to stop. Most of my earlier efforts tend toward the grubby, grimy side of reality, which while it does exist, certainly is not illustrated on the majority of rolling stock seen on the rails. On the other hand, I want to be able to tell I've weathered the car. Combined with a lack of patience, this probably leads me to over-weather a lot of things.
Another challenge is trucks. The slippery plastic that is used to mold HO scale trucks is tough to get paint to stick to. I have had some luck with oil paint, but one needs to be careful not to overdo this as well since the paint can easily fill all the finely molded detail on the trucks.
Finally, wheels are models too. I have been just slapping a layer of burnt umber oil on them, for the most part, although in a few cases this is followed up with some weathering powder. Another work in progress.
Here's one final example of what I've been fooling with.
If you are interested in weathering, one final piece of advice. Set aside some time to listen to the Model Railroad Hobbyist podcast featuring Gary Christensen. His description of the frustrations of learning how to weather, and the revelation that is Dullcoat, are valuable information for the aspiring weathering artist. Gary has shared an article that clearly demonstrates that we don't need expensive equipment or material to acheive realistic results. The guy is truly an artist.