The Polishing Process

Rock of Ages Corporation owns and operates manufacturing facilities in both the United States and Canada. The largest of these facilities is located in Barre, Vermont. This 250,000 square-foot complex is one of the largest, integrated granite-fabrication facilities in the world. Here Rock of Ages produces memorials and mausoleums for the United States market and precision industrial products, such as surface plates and machine bases, for the world market.

Premium slabs chosen for fabrication are trucked from the saw plant to the Barre manufacturing facility. Many of these slabs undergo polishing. The polishing process is somewhat analogous to the process of sanding wood, in that abrasives are used to smooth the surface of the stone. Coarser abrasive grits are first used to rough grind the granite. Progressively finer grits are used during the process to first polish and then to buff the surface to a glass-like sheen.

Rock of Ages utilizes various specialized machines to polish the granite. Gantry-type polishers have the ability to polish large slabs, such as those typically used in the fabrication of mausoleums, or to rough grind slabs that will be used for precision industrial surface plates and machine bases. These polishers use a mixture of silicon carbide powder and water to grind and to polish. The automatic, twelve-head continuous polisher conveys slabs from one set of polishing heads to another. These polishing heads use captive abrasive “bricks” and are capable of polishing over two hundred square feet of granite per hour. Other automated polishers with single heads efficiently polish small surfaces, such as the tops and sides of memorials and markers.