Before revision: In a similar process to sanding, coarser grit Carborundum is applied to the stone and worked with a Levigator, then gradually finer and finer grit is applied until the stone is clean.
After revision: typically a round plate eccentric on a perpendicular shaft,In a similar process to sanding, coarser grit Carborundum is applied to the stone and worked with a Levigator, then gradually finer and finer grit is applied until the stone is clean.