Rocking in Styrofoam

Creating rocks in styrofoam can be a blast. You don’t have to sweat the details so much as ‘go with the flow’. In the following tutorial I used DOW blue styrofoam™. The characteristics vary as to different manufacturers, color and so on. I like the way the blue styrofoam ‘chips’. The Kingspan green styrofoam has, to me, more of a grain or paper-like structure so it tends to tear more than chip. There is still another green board that seems more like florist styrofoam while being much stronger. There is also a pink styrofoam made by Owens Corning. I haven’t played with it but it appears to be similar to the DOW blue foam. The point being that whichever foam you use will dictate how you approach the chipping and carving.

DOW Blue Styrofoam

For this tutorial I grabbed some pieces of DOW Blue Styrofoam. I think this was 1/2″ thick board and a piece of plywood for a base.


Your choice of what to use to glue styrofoam depends on what you can find at your local store. Look for a sealant that specifically is made for insulating foam sheet – Loctite PL 300 Foamboard adhesive is just one of many. DO NOT use white glue as it needs air to set up. You can also use low-temp hot glue.


In this photo I am using a pocket knife to start chipping the foam. The blue foam ‘chips’ nicely .. simply by sticking the blade into the foam and prying it chips or … fractures and creates very quickly what looks like rock (no specific type of rock mind you).

Chipping – cont …

You can see the granular ‘rock like’ surface you get from simply prying up the foam so it fractures.

Fingers too

Here I am simply pinching the foam with my fingers to snap off a piece. Easy peasy. Note to the right where I inserted the blade from the side and pried up to create a small shelf.

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