Abstract: A carriage comprises a base mounted on rollers for movement of the carriage under manual guidance over a work surface, a platform supported above the base on coil springs held in place by bolts fixed to the base and extending up through the springs and the platform, a tool mount slidable along the platform parallel to an edge of the platform and adapted to have seated therein an electric polishing tool with its polishing wheel overhanging the edge of the platform above the work surface, and nuts selectively threadable on the bolts against the platform to compress or relax the springs so as to lower or raise the platform and the tool relative to the base and the work surface.