What you will need: one or more stepping stone molds; spray lubricant; paper towels; a 94-pound bag of Portland cement; several bags of play sand; measuring cups or clean butter tubs; clean water; a mixing paddle such as a paint stick; a mason's trowel to smooth the top of the stone; decorative glass or stones or letter molds to press into the concrete; a moistened cloth towel for curing.
The normal ratio of Portland cement, sand, and aggregate (rock) for making concrete is 1:2:3. However, if you want to make strong, smooth stepping stones that are the equivalent of stepping stones made with commercial craft store kits, you can use cement and sand at at ratio of 1:5. For a 12-inch round stepping stone, I use about seven pounds of this mixture. I like to use a 1-pound butter tub for measuring. One tub of Portland cement to five tubs of dry sand works for me. I measure the dry ingredients into a 3-gallon bucket. I add only enough water to moisten the mixture (usually one and one-third tubs of clean water; if it is like cake batter, it is too wet and will be weaker than if it is just moist. It also will take longer to set up and bubbles will continue to rise to the surface for hours.) A cup of the moist mixture dumped on a clean surface should stand, not slump. If it slumps, it is too wet. I use a spray lubricant and a paper towel to prepare the inside of my mold before I add the water to the mix. I stir the water into the cement and sand mixture with a paint stick. I dump the moistened mixture in my prepared mold and press the concrete down with the paint stick and then with a pointed mason's trowel to smooth it. Today, I let a grandson press his open hand into the middle of the mold, then used reversed plastic letters and numbers that I purchased at a craft store to press his age, date, and name into the concrete near the outer edges of the top surface. AGE 3 - JUNE 29, 2007 - SETH was today's stone, with his age and the date above the handprint and his name below the handprint. I placed the letter and number stamps where I wanted them and let Seth press the stamps down into the cement. Even though the mixture was just moist, a little water collected in the handprint and lettering. I used pieces of paper towel to soak up some of that water. Then I covered the stepping stone with a damp towel to let it cure for a couple of days, rewetting the towel as necessary. After two days, I will carefully remove the stone from the mold and let the stone cure for another day under the damp towel before setting the stone in my garden. I will clean the mold again with spray lubricant and set it aside upside down to be ready for making the next stepping stone. When my grandchildren own their own homes, I will give them their stepping stones to use in their gardens. I will also give them these instructions so they can continue the tradition of making handprint stepping stones. I also create stepping stones that quote verses from the bible. I especially like Psalm 23:3 from the Contemporary English Version: YOU REFRESH MY LIFE. YOU ARE TRUE TO YOUR NAME, AND YOU LEAD ME ALONG THE RIGHT PATHS. It seems appropriate for a garden setting. So is Psalm 37:23 from the same source. These make appreciated gifts for my gardening friends. Cut glass can be pressed into the concrete to make interesting designs; pre-made flower and bird designs can be purchased at craft stores if you're not yet sure how to make your own. A 94-pound bag of Portland cement and several bags of play sand (open them and allow them to dry for a week or two before you start to work with them or plan to use less water in the mix) will make many stepping stones. Buying thick-walled plastic molds may be more economical than thin-walled molds if you plan to make many stepping stones. If you use a 16-inch hexagon mold, you can fit the pieces together like a quilt to make a garden path. Just cut a piece of countertop laminate or metal sheeting to make a divider to mold two half hexagons to fit into the sides of the path to make it straight. It takes about 1.5 hours to make a lettered or decorated stone and three days to cure it. The cost is under a dollar per 12-inch stone. I sell the personalized 12-inch stones for $24, the 16-inch for $32.