UNSW Making

Working with XPS Foam

Tutorials, guides and more! All the things you need to know to form XPS (blue) foam into wondrous shapes.

For this learning module, you will need:

  • Space to create (warning: it's going to get messy)
  • XPS Foam, tools and a selection of sandpaper
  • A dust mask is a good idea

XPS Foam v's EPS Foam


Know your foams!

Extruded polystyrene insulation foam or XPS foam like blue foam is manufactured through an extrusion process which involves melting together the plastic resin and other ingredients. The liquid formed is then continuously extruded through a die and expands during the cooling process. This produces a closed cell rigid insulation.

Expanded polystyrene insulation foam or EPS foam like fruit and veg boxes is manufactured using a mould that contains small foam beads. Heat or steam is then applied to the mould, which causes the small beads to expand and fuse together. This manufacturing process does not form a closed cell insulation as there can often be voids between each of the beads where they are not touching one another.

We use XPS foams for modeling because you can create a smooth surface without voids. It’s easier to shape and sand. There is several different types of XPS foam available and it usually comes down to personal preference.

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What do we use foam for?


Common uses

XPS foam is commonly used for model making because it is easily shaped with simple tools. It's a really useful for quick form studies. Making a tangible item in 3D helps you to understand the look and feel of a product.

In the built environment foam can be used for quick massing models to help you quickly understand the mass/form of the building you are designing or how it fits into it's environment.

Foam also makes quick and easy moulds for casting and forming.

XPS Foam Uses

Working with XPS foam


How to videos of working with foam.

Working with Blue Foam

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Cutting and shaping foam

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Sanding and smoothing foam

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Glue up foam

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Foam on the lathe and CNC

Other Resources


Resources to enhance your foam making knowledge!

Here's some other resources we've found on youtube that you might find helpful.

Some useful websites


Forming techniques


Shaping a surf board

Hot Wire Cutters

Hot wire cutters FAQ

Quick tips for sculpting

Quick tips for sculpting

Check out our Pinterest pages for more examples of XPS foam models

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Get yourself trained!

If you want to learn and/or increase your skills in forming foam don't hesitate to come and chat to a friendly Makerspace staff member. Make sure you complete the Badges that the UNSW Makerspace Network has for you!

Related Badges