Definitley

Era's do dictate the type of weathering. But more importantly, the exact year. Locomotives can be fueled with wood, coal, oil, and other combustibles. Exhaust from steam locomotives, either wood, coal, or oil....produce soot ( not so much dirt ) and can be from a grey ash, all the way up to an oily black residue color. Not only do you have sand deposits, but also cinders along the yard tracks from the coal burning. Most of this was contained in cinder pits, but " accidents " happened along the way, and ciders were common along the yards and the leads to turntables. Water was used extensively for steam locomotives, and the area around the water tower or tank was sometimes wet and muddy, causing a color change along with some rust, mold and mildew.

Early diesels used first kerosene, then oil, and spills were somewhat uncommon, but it doesn't take but a few accidents to accumulate residue at their filling locations. Diesels also use sand for additional traction, and if you are running early passenger service, water to replenish the steam generator. And who doesn't love the first Alco's and their exhaust...with great plumes of black smoke rolling out of the exhaust ? Other locomotives would also have black exhaust, but only due to poor maintenance.

Also take in consideration grade, where they would have had to use more sand, and fuel, to make it to the top. And...add to the equation curvature, tunnels, switchbacks, helper locomotives....well you get the idea. Weathering occurred all along the mainline, as well at the sidings ( Where other opportunities for weathering occur from spillage of commodities ) and the yard and Maintenance tracks.

So,,,not just era, but the exact date and time, and the type of locomotives used, all fit into the true weathering picture. So, try and find photographs from not just your era, but the month and year, and the general area you are trying to model. I just wish there were more color photographs from the age of steam.

Michael

I'm a big fan of the D&RGW

I'm a big fan of the D&RGW and SP during the 1970's and 1980's and by then steam was gone from mainline service for some 15-25 years.  Most of the photo's I've seen from my favorite time period don't seem to show a lot of rust.  I know some folks are big fans of rust but at least for 70's and 80's SP & DR&GW, dirt/grime sure seemed to be prevalent. 

Also remember those western RR's were out west where the environment is much drier as a rule, and there are tunnels which often focus soot onto rail cars following the power sets.  I grew up out west and remember the contrast when I moved to the mid-west, and east - that humidity was much more a part of the environment, especially the summers, and I observed older cars were rusted.  I remember a cousin in Iowa who was into older cars would comment that if you wanted one with a good body, go look in California and buy one there - since they last much longer without rust.  So region IMO plays a pretty major factor in that rust argument.

By the 90's and well past 2000, sure, some rolling stock was showing graffiti, rust etc.  Many can find examples of some pretty sorry looking freight cars and engines.  It's reality sure, but it's one of the reasons I harken back to caboose era trains in the west where I did much of my realy train watching.

As for track, well, in the 1960's and 70's, most of us remember tracks and infrastructure was in a sorry state and had suffered years of neglect in many parts of the country.

Paint

The BIGGEST factor in steam/transition era weathering is paint type. The reason modern equipment fades and rusts like it does is because of lead (actually, the lack there of). Paint "back in the day" had lead (and lots of it) and other chemicals and pigments in it that stood up to rust and sun better than it does today (your house paints not withstanding). Coal smoke and regular "road grime" (ballast dust/mud and oil) are the predominating factors, as well as what I call "wood wear", because paint is just gonna stick better to metal than wood as a general rule. To a point, cars were routinely painted/repainted, so the "re-stencil paint splotches" and also "chalk checks" made by yard crews are also also era-specific weathering highlights, like tagging is today on modern equipment. Of course, rust is ALWAYS going to collect in things like door tracks and other wear spots regardless of era. Check out the Weathering Shop if you really want to delve into the nitty gritty, there are a few of us who don't model the "rustbucket era" (post 1970).

Era

I built the majority of my freight equipment around 30 years ago. At the time, the old Athearn blue box kits were probably the best bang for the buck and along with some decorated ones, I also ordered a lot of undecorated cars which I custom painted for my freelance railroad.

I have seen some really excellent weathering jobs on freight equipment, but I was putting mine together in sort of an assembly line fashion. I would have a dozen or so in different stages of assembly. Painting, of course was first, then decaling and car data was applied. Couplers and wheels, some time trucks were replaced with Kadee sprung trucks.

Modeling the transition era, soot from steam locomotives would be present. I used black chalk to simulate where soot would have streaked down the side of the cars and then a light dusting of "mud" with an airbrush was applied and then the cars were sealed with a clear flat finish. Weathering these cars would only take a few minutes each and all are still in service.

I guess I could have taken a bit more time to put some rust and other weathering on these cars, but I was also in the process of laying track and wanted to move on with construction. These are not highly detailed cars like some of the newer cars on the market today, but when put in a train along with more highly detailed cars you really have to get up close and personal with the train to tell the difference in the detail.

Also, as far as the weathering goes, I am a lone operator and the only person I have to please is myself.

@ Montanan

The point is, you at least took the time to weather your cars. And knowing that a layout operates better when you take time to address and do correctly the mechanical aspects (like track, wiring, benchwork), I think you made the right choice, weather you were, in the end, impatient or not to move on! Your cars don't have to be (nor does the entire roster need to be) prototypical, exacting examples of art, regardless of what the "pros" say. Unless you have a fleet of under 100 cars, lots of free time and money, and most of all, MAD artistic skills, you can't expect to have a layout full of expertly weathered cars and engines.....At least I'VE never meat anybody who does or can met that standard of perfection! When I do a weathering clinic at RPM meets, I always leave off telling the crowd that, "a weathered car, no matter to how much of a level (degree, amount thereof), or to how realistically (and really, what IS realistically?) it has been weathered, it is better than no weathering at all".

 "At the time, the old

I love those old classic Athearn cars, I have quite a few from my childhood. They have pretty much weathered themselves over the years sitting in toy chests and storage shelves. Here's a couple I've had since around since about 1958......DaveB ​