There are "weathered" steam locomotives, then there are "properly weathered" steam locomotives. It's pretty easy to slap some chalks or pastels on your steamer and call it "weathered", but steam locomotives are complex machines, with several different and opposing factors contributing to changing the visual quality of the paint and graphite used on them when fresh out of a shopping...after only a few hours of being back at work on the rails.
As I always contend, to make your model look the
most real, then you need to modify it according to prototype references...in this case (weathering) by using photos of the prototype you're modifying, and color photos preferably.
Since steam locos had fires burning inside them, they were very hot in several places, particularly the firebox and the smokebox...which changed the way the paint or graphite which was applied to those areas looked. Silver paint applied to these areas quickly became a flat, light gray after only a day or two back in service, except on the face of the smokebox, which was cooler than the sides. Other roads applied a blacker graphite (ie. SP) to the smokebox sides, which also muddied up and baked due to the heat. Mud, water and dust from running, as well as water steaming off the surface made the firebox paint, although initially usually the same as the smokebox's, look very different after being in service for a while. Mineral deposits from hard water hotly running down the sides of the locomotives, or steam (also with mineral deposits in it) turned certain parts of steam locomotives nearly white...streaky, dirty white...as well as the drippings from those areas also turned the drivers underneath nearly the same color. If the engine was coal fired, certain areas on it looked really different that if it was oil-fired, particularly on the top and sides of the tender near the filler hatch. Where the water hatches were, they got mineral deposits very quickly from overflow at the water column.
Some engines weathered themselves in particular ways, such as UP Big Boys with a half-moon of dirt & road grime on the lower face of the firebox front, or SP cab-forwards tenders being so dirty that the lettering disappeared. Roads who had less mineralized water to feed their steamers had much less calcification visible on the boilers and tender surfaces.
Since I model the UP almost exclusively (except for an occasional SP train which terminated in Ogden), my steam engines (Big Boys, FEF's, Challengers, USRA light Mikes, and Baldwin Consolidations are weathered according to prototype reference photos as they would appear in the decade starting in 1947 and ending Dec. 31, 1956 between Ogden and Green River. This means that the smaller, less prestigious engines (2-8-0's and Light Mikes) weren't kept as clean as the three "big" engines (Big Boys, Challengers & FEF's), but all were well-maintained, so all of them in various stages between clean and dirty would have been visible in any given day on the Wahsatch Grade.
Here's a photo of a brass USRA UP-ized Light Mikado, showing cinders, dust, heat, coal and water scaling "weathering" in this side view on the Park City Branch:
On the UP, all steam engines' black paint was shiny when applied. IMO this is important as far as our models are concerned too, because this glossy "new" paint is what I apply my dull weathering to...and provides a glossy base to which ultra-flat black (cinders & smoke) is visible mainly by the big difference in surface texture, and not color as with the other weathering effects. Although on this model, there isn't much of the original shiny black that's visible, there is enough there to perceive that this engine's original paint was glossy. Two places that almost immediately went flat on the prototypes were the smokebox and the firebox. Having a shiny boiler contrasting with a flat smokebox and firebox is the first step IMO to a successful steam engine weathering job.
I used Pollyscale paints to this engine after degreasing it with Bestine. I also taped the drivers and other wheels tire surfaces so as not to get paint on those shiny surfaces as well as the traction tires. I then hooked the engine up to a cheap toy 12 volt throttle and let the drivers spin as I carefully airbrushed the bright sides of the NS tires and spoked details...as well as the rods, which, on this engine would prototypically lose their shine after a few months of not being shopped, but kept busy on its daily Park City Branchline Local or Evanston Local duties. I also airbrushed the inside of the coal bunker flat black, and then after precisely applying a light gray for water scaling, I roughened the scaling portions up with a small, stiff brush dipped in alcohol so some streaky black shows through.
Being brass, I cured the acrylic paint with a hair dryer, then removed the tape from the tire surfaces. I do this with plastic too, but with the hairdryer on "medium" rather than high, and it takes a bit longer to cure acrylic this way.
Minimally, the three main areas that need weathering on any steam engine that is active (not sitting in a park) are the smokebox, the firebox and blackening the silver tires and outside wheel surfaces on non-driver wheels. This minimal weathering would represent an engine just fresh out of the shop, or one in either prestige passenger service or excursion service. On the UP, many of the engines which were used daily on several runs would be inspected, lubed and washed almost daily...particularly Big Boys, non-helper service Challengers and passenger steam engines, so during their long tenure on the road, they never got rusty while in service...nor was their paint allowed to fade...even filthy, prototype photos show they were still glossy under their accumulated dirt, soot and dust.
Other roads were notorious for letting their motive power look like Hell, so a little research is in order to "properly" depict the steam engine you want to weather.
As always, weathering tells a story...and when approached this way will make your models much more realistic than mere generic weathering.
Here's a photo of a well-maintained Big Boy heading eastward at Echo Curve on its way to Green River to be inspected, lubed and washed before being turned and returning to Ogden:
Here's a photo of another Big Boy heading west to Ogden and an FEF-2 shoving on the back of an east-bound extra on the reverse-running section of the Wahsatch Grade between Curvo and Ogden:
Have fun!
Cheerio!
Bob Gilmore
