How to work with high-density polystyrene: Part 2

Let’s continue with the second article about “how to work with high-density polystyrene”.

We will illustrate how to prepare a complex and realistic terrain.

When the various layers of polystyrene are well nailed and screwed together, it is better to let the model rest for at least 6 hours, to let the vinavil dry and hold the layers.

To recreate the various shapes of the terrain I use a cutter, but you need to be careful when you use it: never hold your other hand in front of the blade, but always behind it, as shown in the picture.
Once the polystyrene has been cut and worked on in an irregular manner, we won’t continue working it to recreate a “rock” effect, but I will show you a couple of techniques to reproduce walls with plaster and soil.

As you can see it is possible to reproduce everything you can imagine with polystyrene.

Let’s start with how to prepare the floor ; as you can see, in the picture I am preparing resin sheets which reproduce the stone floors of our catalog (but they can be reproduced also directly on the polystyrene, as I will explain in the article about how to carve the polystyrene) ; first they get cut attentively and precisely, and then they get glued using (only) vinavil.

The glue is thus dense, and you should add some token drops of super glue, so that the resin sheets get glued together quickly (due to the super glue), but still allowing them to be moved and glide, to be placed in the right position.

Once the floors are glued, the next step is to plaster the different parts of the cellar.

With some simple wall plaster, and a little spatula (like the ones used in modelism) we start to smear a generous amount of plaster on the polystyrene. This will allow you to hide both the horizontal lines created by the superposition of the polystyrene sheets, and the artificial look of the material.

Once the plaster is dry, you can sand it to remove any sign left by the use of the spatula.

Then, you can proceed with the positioning of the various assembled kits.

On the picture you will note

that you various polystyrene blocks  can be added if needed  be to get some added height or if you need to create some landscape encasing a tower, like I did here.

Once all the kits are placed and fixed (glued) on their relative positions, you can continue working with the plaster and the spatula

to fill any remaining gap or to recreate some particular plaster.

With the help of a brush  wet with water, of small or medium size,

depending on the part you want to work on, you can XXX or texture the wall by tapping lightly the soft plaster with the brush, getting thus an effect similar to a granular wall, where you won’t see the evidence of the brush’s traces on the plaster.

How to realize a realistic-looking terrain:

when I usually look at finished works of other persons, often I see that the terrain looks unrealistic, due to the fact that it is often made with only one kind of sand or gravel, and thus not in scale with the model and work done.

So let’s see how to proceed to recreate a well-made terrain for dioramas.

In the picture you can see different types of sand and gravel.

I use personally up to 4-5 different types of sand and gravel. Let’s start with clay, which must be in low quantity compared to the fine sand. The proportions are usually 1 glass worth of clay, and 2 of fine sand, and then you can add a glass of crumbled brick.  If you can’t purchase it around, you can always buy a classical red brick and break it inside a sturdy bag with a hammer. Just be careful while doing this, and always wear protective goggles.
Then add a glass of river sand (you usually find it in a construction center, where you can also find the mixed gravel). I usually give the finishing touch with a  half-glass of meerschaum powder, but it is not necessary (indeed, this powder usually happens to crackle once dry, so it is a good add-on only for desert landscapes).

Before mixing everything make sure that everything is dry, else, when you’ll mix the clay, you’ll end up with some sort of blocks hard to divide, without speaking of the fact that you’ll lose the wanted result of having a very fine powder.

Another way to obtain a good result is to crumble sheets/blocks of nearly-dry clay.

Just hammer it to get pieces of various dimensions, and then add some very fine sand and some clay in powder.

As you have noticed, obtaining realistic-looking terrain is not particularly easy, but if you prepare it in big quantities, you will be able to use it again for other models and dioramas, and since it won’t get bad, I advise you to prepare a big full sack of it, so this way you prepare it once and then you won’t have to worry about it for quite a long time.

Let’s go back to the model, now ready to receive the terrain.

First we need to brush some vinavil slightly diluted with water on the parts, and I advise you using latex gloves for this operation.

Proceed by 40x40cm section, if you’re busy completing a work as big as the one here. I usually do the same, first dividing the model into 2 or 3 sections, and work on each one separately.

Once the vinavil has been put on all the specific areas


let fall the soil you created immediately on the glue, and press with your gloved hands the terrain against the vinavil, so that it will stick inside the glue much better.

Also, scrub circularly with your hand the terrain.

This is complex to explain, but very easy to realize : the scrubbing is similar to a massage, and allows the terrain to be well spread on all the model, preventing thus unneeded concentrated areas of gravel and terrain.

Continue to drop the terrain once what you dropped previously is now wet due to the contact with the glue. Eventually, when the terrain will have absorbed all the glue, leave it alone, to dry : just go work on another section, etc, until all the diorama is ready.

With a hard brush, remove away any excess terrain which did not glue. With a screwdriver, detach any stone too big on your landscape which creates any esthetic imperfection.

Just remember not to put any stone on vertical walls … so if any got stuck and glued there, use the screwdriver.

If you did everything right, the final result will be similar to the one here in the next picture.

Of course, as for the grass, you can always do your first steps on a simple working area to get the gist of it.

Soon, you will have your perfect and ideal terrain, ready for your own eyes.

End of the second part.

In the next part, I will show you how to carve the polystyrene to reproduce walls, and even a full diorama from scratch.

Until next, Lorenzo “Machiachouse” Marchetto

3 Responses to How to work with high-density polystyrene: Part 2

  1. Brilliant tutorials, Lorenzo. I look forward to trying these ideas out and, hopefully, adding some of your gorgeous terrain, too!


  2. Mike Pierce says:

    WOW! Great tutorial and outstanding work. Gives me some incentive to give this i try!



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: