I've labeled this post 'Plastering' however, that's a bit misleading as I don't use plaster, or Sculptamold, or pre-colored tile grout for my scenery any more. Haven't used that junk in years! I found out the hard way that I was only screwing myself when using those things. Why! Because they dry hard as a rock! If I wanted to make any changes to the scenery, or do something as simple as planting a model tree on a hillside, it took chisels, electric chisel drills, and dynamite to make even the slightest alterations. Now, that's okay if you want scenery that'll be around when the next age of civilization builds a whole new set of pyramids, but for us casual modelers, it's overkill. Years back I started to use this lightweight spackling compound from DAP which comes premixed and hard, but not granite hard. And it solves another problem: the mess that mixing plaster or tile grout creates. Okay, in all fairness, using plaster or tile grout will be a lot cheaper - a whole lot - but if your projects are small then this lightweight spackling compound is just the ticket.
Ed
Before laying down the spackling, I took silicone putty and filled the cracks and voids behind the mountains as well as running a bead at the bottom where the Styrofoam hills met the flat Styrofoam panels.
I covered the hills and the voids that were created when gluing down the chunks of Styrofoam. I also made sure there were some flat inclines that I could pose small lunar vehicle (or people) on. On the flat surface, the spackling was laid down is a sort of fan pattern to make it appear as if the meteor impact which created the impact created the spray pattern.
