Rocky Outcrops

Having a tidy up in the garage, I came across these random shapes. I had made them some time ago, from gap filler foam - the stuff used by builders and plumbers to fill in holes. It comes in a tube and I just sprayed a few blobs on to greaseproof paper (baking parchment). When they were dry I peeled off the paper and removed some of the weirder lumps with a hobby saw. Then I partly brush primed