Extruded insulation foam sheets, easily found at most home centers, have become a popular base for model railroad scenery in recent years. These products have some advantages over the traditional hard shell method but there are a few new challenges too.
Note that not all foam is created equal. While you can use white Styrofoam for some applications, it is not as strong or as easy to shape as the more compact blue and pink insulating foam boards.
Advantages of Foam
So what makes foam insulation so attractive for modeling?
- Light weight. For portable layouts or even multi-level layouts, the light weight of foam is a big advantage during construction and transport.
- Shapeable. You can either cut through the foam with a hot wire tool or carve it with a knife and rasp. Either way, it is easy to whittle away what you don't want as you form your terrain.
- Glue-able. Foam is easy to stack and glue with a variety of adhesives, including ordinary wood or white glue. (Though set up times are increased with these.)
- Durable. Unlike hard shell scenery with a hallow core, it takes a pretty good flex or jolt to crack foam scenery that is properly supported.
- Plant-able. Planting trees, crops and other scenic details is much easier with a foam base. Simply pierce them into the base and they'll be self-supporting.
Like most things, there are some challenges that come with this foam scenery.
- Toxic fumes. Most foam boards, like other oil-based products, can be toxic, especially when melted. So if you do use a hot wire tool to shape the foam, do so with adequate ventilation. Likewise, do not use oil-based paints or spray paint to color the foam. It will melt and make a horrid mess.
- Static mess. Carving the foam with knives and rasps creates a lot of shavings. These are highly charged with static electricity and cling to just about everything. They will vacuum easily however - it just may take you a few tries before you find it all!
- Memory. Most foam sheets will retain a depression if you compress them by leaning on them or place a heavy object on top. This can be a problem if you are trying to use the foam as part of your track support.
- Cost. - The foam sheets are not overly-expensive if you purchase new, but for large layouts the cost can add up. You may have some luck finding used sheets and scraps used for home projects or packing materials.