Add some more styrofoam to bulk up your basic rock shapes.
Add to fill in holes, and to create shapes.
Keep building. The more you can add at this stage, the easier it will be later. It is easier to have too much foam and cut some off than it is to have too little and have to add later.
Once it is bulked out, you can begin to shape the foam with knives, cutters or abrasives.
These marks are made with a drywall saw. Remove any flat factory surfaces.
I fill some small cracks with painter’s caulking.
I built a tiny man to remind me of my scale. I can move him around as I work on different areas.
Expanding foam gap filler called Great Stuff can be used a great glue to hold pieces of foam together and also to fill cracks and holes.
I built the main hall out of cardboard and paper.
This is what the expanding foam looks like on the styrofoam. It is fun to play with, but can be very messy, like super-incredibly messy.
I filled the cracks and holes. I used two cans of the foam.
I had a small bridge from another project so I added it down by the water’s edge.
The Great Stuff expands and leaves blobs when it dries. The edges are rounded so you have to cut it and shape it so it looks more like your rough rocks.
Go ahead, make a huge mess, have some fun.