How I Do Rocks

A new visitor, Bill, sent me an e-mail saying he liked how I do rocks on my layout and wondering if I'd done a post about it. I don't think I have. And the more I think about it, how I do rocks is sort of a moving target -- I did them differently when I started scenery work 20 years ago than I pretty much do now, and I have different rocks on different parts of my layout.

Beyond that, rocks are just part of scenery, and I've had different training in scenery. The biggest influence on scenery for me was when I was a member of the old Slim Gauge Guild in Pasadena in the 1970s. One idea I picked up from it was that a layout could be a big gob of scenery with aisles that let you into it. Another was that vertical slopes increase layout area. Another was that columns, doorways, jogs in the wall, and so forth are things that can be used to advantage if you're creative with scenery. Also, several members of the club at the time were geology professors, which lent a lot to how we learned to do rocks.

There are two main areas on my layout, an eastern division and a western division. I lived on the east coast up to when I got out of college, when I moved with my family to the west coast. I still like and model railroads on both coasts (and for that matter, in between). Here are some east coast scenes with east coast rocks:

These areas date back about 20 years. I did them more or less following a Woodland Scenics video issued around that time. I made individual castings from Woodland Scenics molds using plaster of Paris (not Hydrocal). I tiled them onto slopes made from cardboard strips and plaster cloth, sticking them on with Sculptamold and usng Scultamold to fill in between where needed. It helps to let the castings dry for several days, then dip them in water and stick them on while wet. Then I sprayed the whole area with isopopryl alcohol with a plant sprayer to get it thoroughly wet and then used a foam brush to dab on Woodland Scenics scenery colors.

I followed my memory of rock cuts in the areas I'd grown up in back east for the colors. I was thinking mainly of northern New Jersey, Manhattan, the Bronx, and Vermont-New Hampshire. I can't stress enough the importance of DVDs to get good ideas about scenery. Using the alcohol soaking system, dabbing scenery colors over the wet rock moldings, seems to give the colors a certain amount of depth over and above just painting the rocks. I added a lot of ground foam vegetation to fit in the cracks in the rocks, too. Again, DVDs are good for getting ideas here.

Here is some rock on my western division:

I did these sections the same way as the eastern rock, by tiling homemade plaster of Paris castings from Woodland Scenics molds held on with Sculptamold. However, I mixed up a light tan paint that I used for most of the overall scenery here from interior white latex wall paint mixed with color -- exactly which color, I don't remember. One part of the middle photo above I mixed with Arizona Rock and Mineral pigment and white latex paint. Then for most of the rocks, after the interior latex had dried for several days, I dabbed Woodland Scenics scenery color on with a foam brush and soaked it with isopopyrl alcohol from a plant sprayer, letting the color flow around into cracks. Then I dribbled fine sand and rock onto the overall area and held it in place with wet water and white glue.

The Woodland Scenics video I referred to also talks about using their Burnt Grass extra fine turf to blend things in.

More recently, I used large rubber molds with plaster of Paris poured into the mold when it reaches a pea-soup consistency, then slapped against the scenery base. This was actually how most of the rocks were done on the original Colorado Boulevard Slim Gauge Guild layout in Pasadena. This method has a real potential for disaster, so work to become confident in your technique!

In the case below, I used the large mold technique bordering a finished tiled rock wall.

Any of the techniques I've listed can be used to color this area. It's worth noting, though, that among the lessons I got from the geology professors in the Slim Gauge Guild was the need to complete rock faces with loose talus:

More recently, I've been using flexible foam rock castings from Mountains in Minutes. As I get older and the commercial products get better, I'm likely do do less and less homemade casting and coloring.

Again, it's important to use finer material around these.

When I go railfanning, I often take a couple of old coffee cans with me and collect interesting sand and rock material from the roadside. A collection of different sizes and colors is really helpful.