By Kathy Woolsey
The basic recipe
1 part Portland cement, 1 part fine vermiculite and 1 part sifted peat moss( to remove sticks)
Add enough water to make a stiff mix. Concrete dye can also be added.
Plastic flower pots and Styrofoam coolers make interesting molds.Spray molds with oil to prevent sticking, use 2 bowls or nursery pots one larger than the other. Add enough mix to make the sides and bottom about 2 inches thick add the second (container filled with sand to weight it down). Add more mix between the 2 containers. Shake to get out air pockets. Wrap with plastic and let stand over night.
Stepping stones can be made with
2 parts Portland cement, 1 part vermiculite or sand and 1 part sifted peat moss.
Add reinforcing fibers to the water. Add enough water to make a stiff mix. Hardware cloth can be places in the middle of concrete mix for more support.
Glass beads, sea shells and broken pottery can be added to decorate the stepping stone
Pizza boxes lined with plastic and heart shaped candy boxes make great cheap molds.
Cover with plastic and let dry over night.
The next day
To make the hypertufa look old – after taking it out of the mold- brush with a wire brush so the vermiculite is revealed. Power tools such as drills and angle grinders can be used to carve designs in your hypertufa. Wash with water.
Curing the concrete – wet your pieces and wrap in plastic, keep it wet for 2 weeks or longer. This will allow the concrete bonds to get stronger and prevent cracking and breaking in the future. Later wash with white vinegar to remove cloudy film from glass beads and pottery.