Going from a two-dimensional plan to a 3-D sculpture is easier than it looks. For this project, we’re using 1″ foam insulation sheets. You can find this insulation at most of the large home stores in various thicknesses. It can usually be found in pink or blue – either will work. It is relatively inexpensive, easy to use, and easy to clean up.
Materials / Tools Needed
- 1″ Foam Insulation (A standard sheet will provide enough material for about 2 of the projects shown here – the amount you need will depend on the size and height of your layout.)
- Wood Glue
- Utility Knife
- Rasp / Surform
- Shop Vac
- Hot Wire Tool (optional)
- Dust Mask
Making a Cake
The first part of the process is building up the scenery. This is done by stacking layers of foam to match the contours of the scenery. The boxy tiered scene that results resembles a wedding cake – minus the icing! Precision isn’t very important here, but err on the large side – it’s easy to carve a little more off later.
Since our scene features tracks on a high fill, we started with three squares of foam the size of the diorama. On a larger layout, you would want to find more efficient ways of building up this height, but for 400 square inches it works just fine. With these in place, the outlines of the track and road were redrawn for reference. Then additional layers for the scenery above the track grade were added.
Spread a layer of wood glue between each layer. Use anything convenient and heavy to keep pressure on the sheets until dry. Avoid putting pressure in too small of an area as it will pierce the foam. Books work very well.
Allow your cake to dry for at least a day before you begin carving.
A Scene Emerges
Michelangelo said when asked how he created such beautiful sculpture: “Carving is easy, you just go down to the skin and stop.” Building our scene is no different – but a lot more forgiving! Looking at your layers of foam, all you need to do is remove everything that’s not part of the scene. This is where all that time thinking and sketching pays off. Sketch contour lines around the perimeter and along the top to help guide yourself.
There are two ways to cut the foam. Hot wire tools are sold online, at hobby shows and in some hobby shops. These cut through the foam like a hot knife through butter. One word of caution – melting the foam releases the chemicals within, so do so in a well ventilated area and with appropriate protection. If you don’t want to purchase a special tool, a utility knife and a rasp will work just fine – albeit with a little more mess. This is how we made this module.
Begin by removing chunks with a utility knife. Start at the edges and work toward the middle and from the top down. The size of the knife prevents you from removing too much too fast. Just step back and check your work now and then.
You may end up liking some of the rough, jagged edges left by the knife. To smooth things over, a small rasp or Surform® pocket plane like the one shown here works great. Now a word of caution for this method – keep a trashcan and shop vac handy – the dust will be flying. A dust mask is a very good idea.
Before you know it, your scene is there! There are still a few more things to do – like cutting out for the culvert once it’s made and adding rocks to the cuts and hillside. Don’t worry about the edges – they’ll get covered with a nice finished fascia soon too.