Boulders

 A little while back, on the tip-off of a friend, I bought a Woodland Scenics boulders rock mould. It's a flexible rubber mould for casting boulders in plaster. Of course Woodland Scenics recommend their own casting plaster, but I still have some Linka compound left in a large tub - it must be close to 30 years old, but it still works! I expect dental plaster or similar would work too. 

I mixed up a batch without measuring - mainly because I don't know what the mixture should be - and added some acrylic paint to tint it so possible chips do not show white. When the mixture was creamy I filled the mould, which had first been misted with a fine spray of water and washing up liquid.

Amazingly I'd mixed just enough to fill the mould! I bet I couldn't do that again. After an hour or so I eased the mouldings out of the mould.

They do look like boulder rocks with a nice texture. There's a little variety in size and shape but not a lot. It is amazing how much lighter they dried compared to the colour of the mix. 

The idea is to line the river bank, though I'm not quite sure how to use them. Lined up like this looks too regular, I think a few irregularly spaced with some smaller rocks in between is what is needed. I could try casting another batch partially filling the mould? 

I also need small rocks and stones, I've seen others use cat litter but I don't have a cat...