How to make realistic lightweight fake rocks

Learn how to carve and paint extruded polystyrene (XPS) to make cheap fake rocks for your model scene or diorama. These techniques can be used for model railways (N scale, HO scale, on30 and more) and also look great for gaming terrain such as wargaming tiles and boards. The final shots have some static grass added for extra realism. Foam rocks have an advantage over plaster moulded rocks because they are super lightweight ensuring your board or diorama doesn't become too heavy. The technique is also cheap and only requires basic paints and tools.

[birdie]

The rock structure looks very convincing. The colour is realistic. Thanks for the useful commentary.

[mk]

Finally I founded a simple video of how to carve a rock out of polystyrene😁 Great video, tips and instructions 👍

[Cougartweak]

method I've found useful is to stab in at an angle with a chisel and twist, you get a really nice rough surface that looks really rock like.

[ScottRails]

Beautiful work, great video, thanks.

[rickdee]

Thanks for making this video! I tried a few other techniques before using yours and really like the results. I use a paintbrush and water to blend the joint compound.

[TheDarkArtist]

Great video and great work. Looks awesome

[pacbeltrr]

I'm gobsmacked!! I've been in the Hobby for more than 40 years, and have yet to try carving foam for rocks. From what I can see, it looks better than some work I've seen with plaster! I may finally have to give that a go.
mate, if I carved as fast as you did, I'd end up chopping off all me fingers!!! 😝
Really, I've seriously got to try that.

[TheChromaKid]

Amazing result! Even when you were carving I was convinced it was about 5 times size what it actually was!
Needed a clear tutorial on this cause I'm making a cliff face miniature for a short film and this was super helpful!

[toddknaperek]

Great tutorial, did this technique on my layout and it came out phenomenal.

[joeycarter]

Great video! Easy to follow and brilliant results.

[InvertLogic]

I like how you carve foam! very nice tutorial

[michellediaz]

Awesome!!!thanks!!! I'll try this technique for my terrarium

[CHESEABUN]

Thanks for demonstrating this. I will be following a similar technique for a rock cutting I am constructing. This was. Really helpful. Thanks again
Richard Uk

[jasontrattles]

I have so many off cuts on insulation for this.. who needs plaster and it will be much lighter to transport.. top tips!!

[whdbnrm]

By far the most realistic rocks I have seen in a long time . Your artistic talent is extraordinary right up there with the legendary John Allen and of course Malcolm Furlow . I am excited to creating mountains using your technique . Being a Garden railroader what can I do to make it more weather proof ? I'm pretty sure the foam won't deteriorate if I protect it from the sun . Life span should be 10 years before I plan on moving . Thank you for a inspiring video

[davidrobinson]

Great video, nice and easy going, well done mate.

[stephenfarmer]

Excellent video, thank you so much for sharing...lots of great tips and ideas!

[MissChelle]

Can I use these in an aquarium? Why isn’t there lots of little styrofoam bits flying around? Like bean bag balls lol. Great use of foam!❤️🇦🇺

[philmorton]

Great video, I was dreading this part of the layout, but you make it look so easy, thankyou

[findoe]

Nice work.Some of the most realistic looking rock work Ive seen would be great for aquarium back grounds.