Making Ground Bases

-- NOTE: WIP; photos and other goodies forthcoming --

Often when making a diorama, or when I have a character figure or some vehicle to display, I�ll make a custom base for it that matches the setting where the subject appeared, such as the acid lakeside in Nausicaa, the dusty desert of Deloyer (Dougram), or the rocky paths of ancient Greece (Arion). These bases are typically made from foam and Durham�s water putty.

Materials:

Base � masonite, plywood or OSB, something that putty can adhere to and that can take some moisture without warping too badly. Plastic works too if suitably primed for putty adherence.
Foam � Florist foam blocks, typically available from craft stores. It�s easy to sculpt and shape.
Wood glue, 5-minute epoxy, hot-glue gun � any of a number of tricks to make things adhere.
Durham�s water putty
Mixing bowls
Toothpicks
Modeling / sculpting tools, wire brushes
Flour sifter, sieve, metal mesh
Fine-mist spray bottle (water) and/or clear flat acrylic spray.
Paintbrushes, stippling sponge

The Basic Base

TIP: While making your main base, have a smaller test base next to it and treat it the same as the main base. You can then poke at the smaller base to test for putty dryness without messing up the main base.

Step 1: Planning

Decide the layout and arrangement of the elements on the base � where will the figures or vehicles be placed? What environment elements will there be � rocks, sand, water, vegetation? Check the footing of character figures or models � sometimes characters tend to have problems standing vertically. You may need to plan the location of shims or foam topography to make sure character stands up straight. It often helps to plan for wire pegs to fit into the character�s feet and the base. If your subject has feet or wheels in most cases it shouldn�t look like it just dropped out of the sky. You might want to plan for footprints or tire tracks too.

Step 2: Base Prep

A good base begins with a good substrate - in this case the board. I typically use plywood. It doesn't need to be new; scrap will do. Use wood putty to fill any chips, dings, or old nail holes and sand the surface smooth.
For a nice finished look I paint the edge and underside black and, when the paint has dried, mask the edge off with to protect it from later steps. I think it's easiest to do this first rather than try to mask the finished base from black paint.

Step 3: The starting base coat

If your base is flat ground there�s not much to do in this step. First apply a thin coat of white glue to the base and use the sifter to cover it with a coat of dry water putty. Cover the powder with a paper towl and gently roll it to press the putty into the glue. Let the glue set up and then brush away excess putty.

Next, use the sifter to cover it with a coat of dry water putty. Cover the powder with a paper towel and gently roll it to press the putty into the glue.

Let the glue set up. There will like be glue dripped over the edge of the wood (on the blue tape). Check this for dryness. I typically just leave this overnight. Then brush away excess putty. You will be left with a thin layer of putty glued to the board which serves as a sort of primer for building up additional putty layers.

If all you need is a flat surface, now dampen the surface with the water sprayer and sift on a thin layer of putty. Spray water on top until the surface takes on a distinct yellowish tone. You should not see water pooling in the putty. Let the putty dry. You'll have a good base for flat sand, grass, or similar surfaces.

Need concrete or asphalt? Before water-spraying this coat use the paper towel and roller procedure to compact the surface.

Terrain underlayment

If you need slopes, mounds or bodies of water you�ll need to build some shapes to underlie the putty. Rough-cut the foam to shape and use wood glue to attach it to a wooden base, or epoxy for a plastic base (rough up the base first so the epoxy has some tooth to grip).

Then sculpt the foam surface until your landforms are the right shape. Check your subject�s footing again. Mix up some water putty to a thick, paintable consistency. Pour and spread it over the prepped or roughed-in base. Let it dry. At this point you have a serviceable, basic base. Or for more details, you�re now ready to go on to build whatever ground surface you need.

Details, details, details

This is where the fun begins and the step-by-step ends. Is the ground dry and sandy? Wet and muddy? Rocky or not? Is there water?

Tracks? Meteor craters?

Beyond The Basic Base

Dry / sandy surface
This is the simplest surface type to make. Load up the sifter with dry water putty. Spray over the base coat with water or acrylic spray, then sift some putty all over the base. You can repeat the wet-and-sift layers a few time if you want. If you see that the top coat of putty getting wet spots, sift some more putty over those. When everything�s dry, tilt, tap, and brush away excess putty. Apply a sealer coat of acrylic before painting.

Wet / muddy surface
Make up some thick, goopy putty, spread it over the prepared base, and go play in the mud. Use blunt modeling tools, brushes, and sponges to shape the mud. Adding tracks to the mud will add to the realism. Dust a thin layer of dry putty over the surface if you want a gritty look.

Rocky Surfaces
Wind-sculpted rocky outcrops? Scattered river boulders? Rocky scree? You can do them all with water putty and of course, some practice.

Boulders � break up florist foam into chunks and roll them around between your hands to smooth the edges. Stick a toothpick into the foam and dip into some thickish water putty. Set aside to dry. When nearly dry, remove the toothpick and clean up the surface. You can sculpt into the surface at this point too. When the putty�s fully dry paint the boulders.

Scree � spread putty onto plastic wrap and let dry. Then break it up into chunks for rough, angular rock pieces. If you break it up while not fully dry and roll the chunks around you can get small rocks, cobbles, and gravel.

Outcrops � build up and sculpt a foam base into the shape of your outcrop. Pain some thick putty over the surface and let it nearly dry. It will be solid but still feel cold to the touch; you should be able to dig a fingernail into it. Use sculpting tools and wire brushes to etch and shape the putty surface.

Making tracks

Whether footprints, wheel tracks, or some other type of track, adding them will add to the realism of your base. Keep in mind the type of ground you�re making. Sand tends to fill in, soft moist ground can show clear detail in shallow impressions, mud can show soft detail in deep impressions.
If you�re planning way ahead and making the base while your subject is still under construction or unpainted you can use the things feet to make tracks. I�ll often make a resin casting of the foot or wheel before construction and use the casting for track making. This keeps the model part clean.

Water

There are a number of clear materials that work for standing water � hot-melt plastic, clear resins, epoxies. Find what works best for your use.

The Model Citizen's "Sprue U" pages are �2000 Roger Sorensen
page URL: http://employees.csbsju.edu/rsorensen/modelcitizen/sprue_u/.htm
last updated 12 November, 2012