There are numerous techniques for carving stone and each depends on the type of stone, the scale of the sculpture and the complexity of the composition.
This short video shows me working on a large, abstract sculpture which I am carving from Carrara Petacchi marble. There are over 65 different types of the lovely white marble that is quarried in the mountains above the famous Italian town of Carrara. The Petacchi quarry yields this grey/white variety which has striations of grey veining and has a high content of magnesium, so the marble can live outdoors in cold climates.
Since the abstract has large concave curves, I am using a technique called fretting. Working with a 5”, 12 amp Metabo angle grinder, mounted with a diamond turbo cutting blade that has a matrix specially for marble, I make parallel cuts in the marble about 1” apart. I cut as far as the blade will allow, or about 1.5” You will notice that I feed a small amount of water over the blade which goes into one side of the curf. This keeps the blade cool and keeps the dust down. Since most angle grinders are double insulated, one can run water and not get an electric shock. I’ve used this technique for 25 years and never had even a tickle. Most diamond blades are made to cut dry, but I find they cut faster and last longer if cooled with a small trickle of water.
Once I have done a course of cuts, I then take a hammer and carbide tipped bladed pitching wedge and knock off the pieces, or frets. When they come off, they look like fat marble fingers.
I use the technique of fretting for a wide variety of stone, including limestone, marble and granite. One can remove an incredible amount of stone from a sculpture per hour and with relatively little effort, as the angle grinder does most of the work. I use a 5” angle grinder, as it is lightweight yet powerful. Yes, you can use a larger angle grinder with a larger cutting blade, but it will be much heavier and more wieldy to use and result in quicker physical exhaustion. As you are working a small area, you can be flexible with your removal, unlike larger ring saw, or chainsaw blades.
I remember walking up to my 6 foot tall marble block at Studio SEM in Pietrasanta, Italy with my little 5” angle grinder and hearing snickers from the artigiani. After a day’s work, I was standing shin deep in stone chips. “All you?” was asked from a shocked worker who could not believe the amount of stone I had ripped off. I just shrugged. I felt a bit chuffed that I had introduced a new technique to a tradesman who was working in the time honoured marble carving tradition.