In addition to these fine photos of some of the preparation, we have pictures of teams retrieving the second clue.
Once we had everything worked out, making the cement bricks took about three hours of work and two days of drying for each batch of three. We made two prototypes and five batches of three. Three bricks required 100 pounds of cement, lots of water, 60 inches of steel bar (cut into twelve pieces), and various other goodies, all carefully prepared. Each brick weighed about 40 pounds when dry and cost about $10 for materials. We had lots of fun making and testing prototypes.
We finished the last of the bricks a couple days before The Game. We loaded up Seth's car and he hauled them over to his place, where they sat under a tarp in his bedroom.
The morning of The Game, after we'd set up all the other clues, we wrapped up the bricks and arranged them in Seth's front yard, where the game would begin. It turned out that there were only ten teams, so Seth still has four more bricks.