Boxcars and covered hoppers
The corrugated steel roofs on prototype boxcars rust in a variety of patterns. In addition to rusty metal, boxcar roofs may have paint overspray and sealant patches to prevent leaks.
Covered hoppers are also prone to rust. What sets hoppers apart from boxcars are the occasional spilled (and sometimes growing) grain on the roof and the rust-free hatch covers. The covers used on most new hoppers are Fiberglas or aluminum, so at most they have a layer of grain dust and road grime.
Two-step weathering
I used a two-step system to add rust to the roofs of my HO scale freight cars. First, I added rust brown powdered pastels and a little black powdered pastels to a clear flat varnish, mixed everything together, and applied the rust paste on the roof in a random pattern.
Then I applied the same two shades of powdered pastels on top of the painted areas. I used a wide, soft brush to distribute the pastels. I sealed the weathering with a coat of clear flat varnish applied with an airbrush.
I used the same techniques on covered hoppers. The hatch covers have a bit of dust and grime on them, but no rust.
Not-so-empty gondolas
On a recent trip to the Midwest, I discovered unloaded gondolas aren’t always completely empty. While photographing trains from a bridge, I noticed several gondolas with debris from previous loads. Wood, dirt, and non-magnetic metals were common sights.
To re-create this look, I masked the sides and ends of the gondola and sprayed the interior with Model Master Leather. After the paint dried, I broke up the interior’s uniform appearance by applying light rust, medium rust, and black powdered pastels with assorted brushes. After sealing the weathering with a clear, flat varnish, I randomly applied blotches of white glue thinned with water to the car’s floor. I placed pieces of stained stripwood into the wet glue, and then sprinkled in real crushed rust flakes. When the glue had dried, I shook out the loose material.
While this article focused on weathering roofs, I of course weathered the rest of each model. You can learn more about my techniques in the January 2009 Model Railroader.











