Posted 31 Jul 2011 at 13:51
I've been looking at making my own hills. Big hills to complement the smaller commercial hills I've already purchased. I knew I should use High Density Polystyrene which is otherwise called Blue or Pink Foam. But I was struggling to find that. Luckily, after a bit of googling, I found a good explanation of Styrofoam on Blue Foam, Pink Foam, Foamboard and Styrofoam.
What is Styrofoam?
The fluffly white stuff used in packaging is also polystyrene but is expanded polystyrene. Don't use this for modelling as it is far less durable.
The stuff you need is High Density Polystyrene. This is also called extruded polystyrene because of the production method used. It is also known as Styrofoam after the leading brand.
The colour doesn't matter so forget the "pink" or "blue" foam of a few years ago. What matters is the density. Get a density of at least 32kg/m3. Denser is ok (right up to 200kg/m3 foam which is used to make surfboard blanks)
Where to find Styrofoam?
Google for “Styrofoam” or “Underfloor Insulation”. Typical brand names are:
- Styrofoam LBX / DOW Styrofoam IB (UK/USA/Eur/Aus/NZ)
- Floormate (UK)
- Foamular (USA/Oz)
- Styrodur (Europe)
- Roofmate (France)
- De-Q-cell (Germany)
- Depron foam is a denser brand and hence good for thin features
For 600x600mm styrofoam tiles check out
- Antenociti Workshop (claim their styrofoam is harder than that from Craftfoam)
- Craftfoam from Panel Systems
For 10mm sheets
For 2mm MDF to use as a backing sheet
My hills have between 12mm (1/2") and 25mm (1") elevations. But horses for courses.
Increasingly I think lower highs are better as the figures are more likely to stand on them without falling over.
Some of my commercial hills are 10mm foam (per level) backed by 2mm MDF.
How to Glue Styrofoam
Wood glue (e.g. PVA) might not work because it dries with contact through air. Some foams allow air to penetrate but many don't. You can do an experiment by gluing a couple of foam pieces together and waiting 24 hours; when you prize the foam apart you know you've got an ok glue for that foam if the glue has dried in the middle.
A sort of middle ground is to use a hot glue gun in the middle (without the glue being too hot or the foam will melt) and PVA around the edge
Probably easier to use appropriate glues such as UHU Por or Foam-2-Foam to stick styrofoam together.
- Optional step 1: Glue 2mm MDF to back of Styrofoam
- Cut the Styrofoam into hill shapes with an old bread knife. The serrated edge helps. Do it bit by bit.
- Rough up any flat surface remaining on the upper surface by scraping with the serrated edge of the knife.
- Glue together layers if you want multiple elevations
- Glue small rocks to the upper surface with PVA
- Glue sand to upper surface with diluted PVA
- Paint brown
- Dry brush lighter colours
- Glue (with diluted PVA) flock in patches.
See my Flocking page for more advice on the last few steps.