I weather my cars based first on their age, and then, for the most part, on their service and where they would have most commonly operated. Hoppers, both open and covered, along with gondolas and flatcars, are the ones most likely to have their weathering reflect their service.Most of my flatcars and gondolas are fairly recently built, and don't yet show much of the abuse to which these cars are often subjected.
This gondola was picked up used, with poorly-applied D&H lettering hiding the factory-applied PM lettering. I stripped away both, then added metal grabs and sill steps. The car was then repainted and lettered for Lehigh Valley, using Champ decals. Even though it's no older than my home-road gondola shown above, it got the soldering iron treatment:
Some old blocking and dunnage material, along with a generous helping of loose dirt completed the "used" look:
Besides using paint as actual applied weathering, it can also help to show a car's age. This automobile boxcar, built in 1916, was last re-weighed in September of 1935. It still has only a single grab iron on the end of the side to the left of the door. By the time its next re-weighing is due, in March, 1938, it will have either been scrapped or re-built into a steel-sided car, with either double- or single-doors.
Here are some home-road steel boxcars built in 1924. Some time after they were built, the original doors were replaced with the ones shown. Then, in 1931, the original roofs were replaced with Viking roofs, and the original trucks with National B-1s. The cars were also repainted at that time. In 1934, the original K-type brakes were replaced with AB-type, and the second grab iron on the left end of the side was added in 1936. So these are 14 year-old cars, but not especially beat-up or overly dirty.
Since I don't use out-of-the-bottle weathering colours, cars weathered at different times are unlikely to be identical to ones done previously, and even within a single weathering session, there may be 6 or 8 colours in use, and in various combinations and/or intensities. When a particular colour is almost finished, what remains in the bottle is either dumped in with something else, or merely re-filled with only thinner. This makes a weathering colour which can often be sprayed over the entire car, subtly changing the car's colour without itself being noticeable.
Some older cars can be quite dirty...
...while this almost-new (October '39) reefer just barely qualifies for my chosen "late '30s era", and is little-weathered except for some road dust:
This car, a couple of years old, got an overspray of its own colour, severely thinned (about 90% thinner) to tone-down the starkness of the lettering, then a light application of road dirt and grime:
Wayne
The weathering I apply doesn't really depend on the type of car as it does what the car is used for.
As for weathering new cars, I generally give the bottom edge a light earth color (tan), along with the trucks. Then apply a coat of Dullcote to kill that new car sheen.
Marlon
See pictures of the Clinton-Golden Valley RR
What (if anything) differently you do for weathering different types of freight cars? For instance, I've read some use a soldering iron near a gon or open-top hopper to bend the frame. Not looking for weathering tips in general, but specific cars.
Also, you weather more for older cars? I've got newer ones that I just remove the glossy look,
TIA!