How to Run Cement & Sand Molding on a Bench

Place two 32-by-5-by-1-inch pine boards parallel to one another resting on their 1-inch sides. Place two 5-by-5-by-1-inch pine boards perpendicular to the 32-inch boards. Rest the smaller boards against the side of the larger boards. Hammer two 4-inch nails through the side of the larger board into the end of each smaller board.

Place a 34-by-7-by-1-inch piece of plywood on top of the rectangle you created in Step 1. Hammer 2-inch nails through the plywood into the edges of the boards. Space the nails every 2 inches.

Turn the five-sided box upright so the open side is up and the plywood is against your work surface. Fill the five-sided box with 2 pounds of playground sand. Use your hand to dig out a 28-by-1-by-1-inch rectangle from the center of the sand. Press the sides of the sand to smooth them.

Press colored-glass stones, shells or pebbles into the sand. Leave half of the stone above the level of the sand. Use any pattern you like.

Prepare a 1-pound bag of cement. Mix the cement according to package directions. Mix in enough water to achieve the consistency of pudding. Pour the concrete into the sand mold. Smooth the surface of the concrete using a trowel. Let the cement set according to package directions. Although times may vary, most concretes recommend 72 hours.

Remove the concrete strip from the sand. Use a garden hose to spray the sand off the concrete strip. Let the strip dry for three to five hours, or until completely dry.

Apply a 1/4-inch layer of concrete to the back of the concrete strip using a trowel. Turn the bench on its side. Press the concrete strip to the concrete bench along the edge of the bench seat. Leave the concrete to set for 72 hours.

Turn the bench upright and place it where desired.