Part 01, Part 02, Part 03, Part 04
With the rubble pile finally set (the grout and PVA took a while to go off), I have given the base and rubble a coating of sand.
I spread PVA glue evenly over the base, but added it in a much more patchy way over the rubble, hiding most of the grout but leaving patches of the polystyrene exposed.
The exposed polystyrene will be painted up as stone.
I added some sand to a few other places on the model too. To help give the aged, ruined effect it breaks up the even surfaces nicely. It also hides seems and joints quite well.
In this photo you can see the wrecked door of the tower. I made this with a piece of balsa wood that I scored planking lines into and then cut away pieces at each end to show where the wood has rotted!
In the final photo you can see where I have marked the boundary between the inside of the buildings and the outside. The sand stops on the door step. I should probably have raised the floor height above ground level a little and added a door step. I will remember to do this with the next ruin I do...