I am making a model that requires me to shape, paint, and glue something that will represent small stone slabs (1/2 thick). I do not have access to power tools. I need to cut out unique shapes and then sand them down considerably to make a dome. I was thinking about plaster board but the material I need does not need to be that sturdy. I basically need something between plasterboard and styrofoam (if that makes sense). Any ideas would be appreciated.
Foam core board may work. It is a foam board with oaktag (thin cardboard) on both sides of it. Comes in different thicknesses, just google it.
I have no idea why you would make a dome like one would make an iglu? When you could use plaster of paris in the same why you'd do paper mache or putting an arm in a cast. Blow up a ballon to just under the size of the dome you need then apply the plaster thicker when you get close the size you want so to be able to cut it to size and sand it smooth.
How about polymer craft clay? You can get it in craft stores (like Michaels or Joann Fabrics in the US). It comes in a block and you can easily break off or slice chunks to the size you need. It comes in a range of colors (or can be painted when dry) is easily shaped and rounded (no need for tools or sanding) and once you have the shape you want you just bake it in a low oven (275 F for 30 minutes) and then you can paint the pieces if you like and glue them together. It's pretty cool stuff. I just made some miniature props for a movie out of it. Might not be an option if you need a lot of it but you did say this was a model.
