Realistic Model Railroad Scenery
Construction Techniques on a Budget

Making This, Using Nothing but That – Part 1

There are a number of different kinds of foam products which can be used for constructing scenery features. Extruded polystyrene foam is a fairly dense material used for home insulation, usually found in pink (Owens-Corning) or blue (Dow) colors in sheets of two or four foot width and four or eight foot lengths and various combinations of those measurements and thicknesses. Most home improvement stores such as Lowe’s and Home Depot (in the USA) stock the products, although if you can find a home construction site you may be able to find small quantities of odd sizes and shapes of scrap free for the asking.

The one thing you will experience working with foam board right away is the mess. If there is one tool that will make your life much easier when cutting foam, it is a portable shop vacuum, or a full sized one with a long hose. Shaping foam produces huge quantities of statically charged time foam particles that will stick to anything. It’s impossible to clean them up by picking the individual pieces, as they stick to your fingers. Keep the shop-vac handy, and if at all possible, you might want to do your foam work outside of the house. Your spouse will be much happier if you do!!
For the initial shaping of elements such as rock faces and mountainsides, he foam is easily cut using a sharp knife such as an X-acto or a utility blade. You can also break the foam easily by using the same sharp knife and a straightedge to score a line and then break the board over the edge of a table or workbench.

Another useful tool for working with extruded foam is a hot wire cutter, such as the one available from Woodland Scenics, or a hot knife such as is used for candlemaking. Either of these will allow freehand complex shapes to be easily created. Be careful, the tools are HOT, and also do this in a ventilated area because the melting foam does exude a noxious odor that is no fun to breath.

For larger features, cut pieces in a “layer cake” fashion and stack them to give you the desired height for your terrain. Assembling the layer cake is done using foam-specific construction adhesive such as “Liquid Nails for Projects” or a similar product specifically designed for the foam. Avoid adhesives that melt or destroy the properties of the foam.
If you take a look at a photograph of a rock face, you should immediately notice that nature doesn’t do things tidily.

There are seldom straight lines and the contours of outcroppings and rock falls tend to look like they were actually gouged out of the earth by some giant hand. In fact, this is one of the open secrets to rock and mountain scenery that you can easily master. A couple of inexpensive tools are going to be essential for this. First, a drywall saw with a blade about a foot long or so. This will allow you to make large area cuts from which you will get to finer and finer detail. The sharp point on the blade is also useful for gouging out rock falls and faces. Second, an unmounted hacksaw blade can be used for finer detail cuts and smaller areas where the flexibility will allow curved sections to be removed or shaped. Cover one end of the blade with duct tape or electrical tape to protect your hands, and be sure to wear a pair of work gloves when using tools with unprotected cutting edges. Next, the same utility knife mentioned earlier will be a handy gouge tool. One with an adjustable length blade is the most useful, but any sharp bladed cutting knife will do fine.

Make your deep gouges with a long-handled screwdriver, prying out the chunks of foam as they come free. For wider areas, the corner of a metal putty knife is a convenient tool.

Last but not least, a Sureform rasp tool is ideal for roughing up smooth areas of foam to simulate uneven ground.

One railroad feature that is often overlooked in constructing a model layout is that the right of way is often elevated, which creates ditches along the route for drainage and also provides a stable and leveled right of way. Using extruded foam for construction makes it easy to raise the roadbed above grade and include prototypical ditches. The photo shows a piece of test track elevated on a 2” piece of extruded foam. This is probably too high for most applications, but it was available at the time the test track was built. 1” would probably be a better choice for general purpose use. Make the foam a bit wider than the roadbed you are using so you can make a ballast “shoulder” next to the track.

Because it’s very light, bead board might be a good choice for a small N or Z scale layout base. However, bead board is also easier to break than extruded foam and so is not as durable for the base. This lack of strength is also a drawback when considering what type of stress might be on foam scenic elements such as approaches to large heavy bridge structures. Nonetheless, bead board is cheaper than XPS foam and shouldn’t be discounted out of hand for the right application. Again, using an adhesive such as Liquid Nails for Foam Projects is the best method for adhering items or sections to each other.

There are commercial products made from EPS foam. For example, Woodland Scenics manufactures track risers of EPS that are very convenient ways to create consistent grades on your layout. They come in sections about three feet long, for several scales and grade percentages. The risers are manufactured in such a way that they can be curved into whatever right of way arrangement suits your layout.

Foam Core for Model Railroad Construction

Foam Core is also an expanded foam product. However, foam core products consist of a laminate of EPS sandwiched between two layers of paper. This gives a surface that can be drawn on and acts to keep the waste spheres under control. Rather than as a base product, foam core is very useful to create structure walls and man-made elements of scenery such as drainage culverts and the like.

Foam core can also be used for small scale layout bases. It comes in thinner sizes than EPS sheets, and is typically found in art stores rather than home improvement centers. Sizes are not standard 40 inch x 60 inch sheets, but tend to be sizes popular with artists, who use the sheets for project backing. Another use is for lightweight signs and banners.

Foam core is best cut with a straightedge and an X-acto or utility blade. Some foam core products are available that have foil or plastic covering rather than paper. They are marginally stronger, but painting the foil might require the use of a different paint medium. Plastic covering can be painted with acrylic paints just as your plastic rolling stock would be.

PART 2