Asphalt tank cars, Part 4: weathering

In my three previous posts on these tank cars, I showed prototype photos of asphalt cars, along with models built to reflect those photos. The most recent post has links to the first two of those posts (that post can be found at the following link: http://modelingthesp.blogspot.com/2016/09/asphalt-tank-cars-part-3.html ). But all the model tank cars shown previously were unweathered. Now I want to address weathering.
     My weathering procedures using acrylic tube paint have been described in a pair of Reference pages, as they are called, and links to them can be seen at the upper right of this blog page. As I mention there, I weather most cars in two steps, sides and ends separately from roof, top or interior. But with tank cars, that really isn’t a practical division, and they have to be weathered in one session, over the entire car. But with a little practice, this works all right.
     For these asphalt cars, my first step is a moderately heavy “dirty” layer with my usual (and varying) mix of Black, Neutral Gray, and Burnt Umber. This not only makes the car dirty and with a grayish aspect, but also, importantly here, dims and tones down the vivid white lettering on the black car. I can illustrate with the Western Asphalt model shown in the first post in this series. Here is the car, in its as-lettered state (a slightly different photo from the one in that first post),

After giving it a weathering wash of the kind just described, CDLX 1127 is shown below from almost the same angle. You can compare the two views. Cutting down on the brightness of the white lettering makes a big difference.

     Next, I wanted to suggest the crusted asphalt spills that are visible in some of the prototype photos of these cars. It’s natural that the spills would look that way, because asphalt is quite viscous and sticky, and spills can readily clump and build up. Acrylic tube colors are a little that way too, so my first effort was to daub brown and (mostly) black onto the dome top and sides. In the photo below, you can see the three-dimensional quality of the result.

I did the same to the CDLX car leased to Shell Oil, CDLX 1077 (see my second post in this series), though I chose not to weather the car to as gray a state as with CDLX 1127.

Both these weathering jobs have satisfied me with their overall appearance.
     There have been suggestions that gluing a little fine sand on the dome surfaces, before doing the spills, would give a rough texture to the spilled area. I haven’t tried that. One of my earlier models was given the spill representation by just backing away with the airbrush until the paint plume dried in the air, creating the familiar “sandy” surface that occurs that way. This looked all right but was pretty uniform. That is what you saw in my second post in this series, on the Overland brass model of the Western Asphalt scheme.
     Last, let me mention again that the reduced price for the starting point of these models, the Proto2000 (now Walthers) convention tank cars, is still in force. That special price, for a limited time only, is $10 for the car, $7 shipping within the U.S. Go to the 2011 convention store (still open at: http://www.x2011west.org/store.html ) to buy the cars, as long as supplies last.
     These “asphalt” acrylic build-ups are a little bit of a caricature, but in HO scale, I think they are all right, and in fact look as they should at layout viewing distance: just noticeable as some extra spillage. Perhaps not good enough on a contest model, but fine for my purposes.
Tony Thompson