For the outer walls, I essentially built two boxes, each 10″ long, 3.5″ high, and 3″ wide. I used the Wall Builder mold (#200 in the Hirst Arts line), casting it twice then doubling it to make half of a section of a side of the box. That means that you need to cast it eight times (four times a side) for an entire wall section. Because the mold’s length is only four inches, I added two inches to the end using regular blocks, and used regular blocks for the short sides.
For the top, I cheated once again, but this time the cheating caught up with me. I used some custom molds I had made a while back to cast 3″ wide floor tiles to go across the top of the “box.” But there’s a problem. Sometime when casting using silicone rubber, there is a bit of shrinkage. It is usually not noticeable, like 2%. Two percent of an inch is nothing, but when you then have that add up over ten inches, it becomes almost a quarter of an inch shortfall, which you can see on the edge of the wall. This was made worse because I glued 1″ by 1/4″ by 1/2″ tiles along the side of the upper floor to make part of the raised crenellations, and now it is really noticeable. I may have to dremel the lip off a bit to make it flush with the undersized bricks as a result. Or, I could not be so much of a perfectionist, one of the two. On top of the narrow floor tiles, I glued 1/2″ square blocks for the crenellations.
Anyways, you basically make two of these wall sections, that are nice and deep so you can have some fun man-t0-man combats on them (and reflect the historical reality of the walls themselves). Next, I’ll be building the three sides of the inner walls.