Stone carving can seem like one of the most intimidating of the physical arts, as stone is one of the least forgiving mediums. A slip of the chisel or crack in the stone along crystal veins can irreparably alter the shape of your stone, which will force you to modify your sculpture. But careful planning, flexibility in your designs and a light hand are all that are needed to tackle this tricky medium. For beginning sculptors looking to gain some experience, it’s best to begin with the softest stones like limestone, soapstone or alabaster, as they are easier to carve, more forgiving and have less veining to contend with.
1. Measure the dimensions of your stone, and create a replica (either the same size or scaled down) with your modeling clay.
2. Sculpt the clay with your clay tools into a model of the sculpture you would like to carve in the stone, making any design adjustments at this time. This step is essential in stone carving, as clay is an additive sculpture medium. Removed clay can be added back in as you work out any structural issues in your design that might result in your stone splitting as you carve.
3. Wrap the metal head of your hammer with a thin rag and secure with duct tape. As these soft stones are easy to carve and relatively fragile, it is necessary to protect them from the vibrations of metal striking metal that will result in cracks. Muffling the hammer with the rag and duct tape reduces these vibrations. If necessary, fasten your stone down to your work table using c-clamps at this time to prevent it from sliding while you carve.
4. Begin chiseling channels in the stone on the areas that will be removed from your sculpture, with your hammer and your point chisel held at a 45-degree angle. This will leave long, narrow rows of raised stone on those areas that will then be removed. For large areas, it is recommended to have these channels crisscross, which will create sections of raised stone squares instead of rows.
5. Insert your tooth chisel into the channels at a 70-degree angle, and hammer with upward swings to lift out the raised stone areas. Alternate between sides of these raised sections to break it away from the sculpture slowly and evenly from all sides. Do not try to force these sections out from one direction alone, or your stone will be more likely to crack.
6. Compare your roughed-out stone form to your clay model to determine if you’ve removed enough bulk stone to move on to finishing. If your stone form does not resemble your model in both size and shape, repeat steps 4 and 5 until you achieve the appropriate rough sculpture.
7. Shave off the highest, roughest edges of the stone gently, using the flat chisel and the hammer. Unlike the the work you’ve done with the point and tooth chisels, which focuses on removing the bulk of unwanted stone, the flat chisel instead follows along the lines of the stone form to smooth down the rough form closer to the final shape.
8. Smooth down the form of the sculpture to the final desired shape, alternating between the rasps, which are used for overall smoothing, and the rifflers, which are used for fine detailing. Note that the stone will still be somewhat rough at this stage, but there should be no extraneous stone sections protruding from the final shape.
9. Use the screens, wet and dry sandpapers and polishing powders provided in your stone polishing kit to smooth your final sculpture, following the instructions included in the kit. Congratulations, you’ve just carved a stone sculpture!