Bushwhack Canyon Part Two: Paint Preparation

After the top cardboard was glued and dried,  I applied spackle around all the top edges:

Then using a crappy bigger brush, I brushed to tops with Elmer's glue, diluted with water, and then spread a coating of sand across them.

I would have done more, but physics forbade me, I needed to wait until the spackle dried before painting the whole thing.