After staring at some of the beautiful covered hopper cars that Tom Johnson posted on the MRH forum (http://model-railroad-hobbyist.com/node/14896), I thought I would try my hand at a few of them. And once he posted a tutorial on his weathering techniques, the die was cast- I had to give it a try.
The two TGCX cars were weathered using water soluble oil paints and Micro Scale's Microsol as a thinner. I picked up this technique from Rich Divisio on the old Model Trains Weathered website, which is no longer available. The technique involves thinning some of the oil paint on a pallet, applying it to the model, and then removing it with gentle dabs of a brush that's clean. It's a great technique for adding the typical accumulations of dirt and crude that build up on the ends, bottoms, and tops of cars, but I didn't have much success initially in getting the streaks on the sides that I was after. The paint wouldn't come off as it had previously- perhaps I let it dry too much or put too much on. In any event, I went back over the sides using a brush that had been dipped in 70% isopropyl alcohol and then wiped almost dry on a paper towel. The streak effect worked OK, but I didn't get the fine lines that Tom J. has been able to capture on his cars.
Next up is a covered hopper that I weathered for John Miller after he painted the car and added the decals. The first step was to spray the sides and ribs using a custom dirty brown mix of Floquil paint. I then wiped the ribs with a Q-Tip soaked in Turpenoid to remove the spray. Next, I used Windsor & Newton oil paints thinned with odorless Turpenoid to add the streaks to the sides. Tom J.'s tutorial was instrumental in helping me learn the techniques for the streaks. I use a small block of wood held parallel to the ribs to guide the brush as I pull it down the sides. This helps insure that the streaks are straight. The trucks were painted with Rust-Oleum's camouflage brown and then given a light coating of weathering powder. The bottom and ends were weathered using the techniques outlines in Tom J.'s tutorial.
For the CWE covered hopper, I used the same techniques that I used on the K&LE car. The primary color used for the streaks was Van Dyke Brown. As these cars haven't been in service all that long, I kept the rust marks and steaks to a minimum.
This is my first foray into oil paints in many, many years, and the first time I have used them for weathering the entire surface of a car. While I need a lot of practice, I'm reasonably pleased with the way these cars turned out. It's been fun to explore some new mediums and to see the effects that can be created.