Electopolishing is a cleaning operation, not a polishing operation. Electropolishing makes the surface brighter, not smoother or shinier. It is done to chemically etch a number of layers from the surface of the metal (usually SS) which will take all of the surface contaminents with it. The surface may be brighter because of electropolishing, but it will not improve the ra of the surface. If anything, it will degrade it slightly.