Abstract: A portable water-driven rotary tool for drilling, grinding and polishing concrete and stone that provides for high torque and that uses water pressures as the power source, the tool including a water control valve, an impeller with blades and a drive shaft that has a longitudinal axial water passage disposed therethrough for diverting water used to power the tool onto a work surface for lubrication and as a cleaning agent.

Abstract: A portable water-driven rotary tool for drilling, grinding and polishing concrete and stone that provides for high torque and that uses water pressures as the power source, the tool including a water control valve, an impeller with blades and a drive shaft that has a longitudinal axial water passage disposed therethrough for diverting water used to power the tool onto a work surface for lubrication and as a cleaning agent.

Abstract: A method of preparing a smooth watertight concrete in-ground pool surface that eliminates the use of a plaster outer surface layer that includes allowing the concrete pool body to cure for at least thirty days at which time a grinder is used to grind the surface to a smoothness and depth that is watertight and that exposes aggregates within the pool surface resulting in an aesthetically desirable permanently finished pool surface.

Abstract: A method of preparing smooth, watertight concrete in-ground pool surfaces. The present invention includes the steps of preparing a pool site by digging an appropriately sized ditch, preparing a concrete mixture and filling the ditch with the concrete to form a structure. The concrete surface is treated with an appropriate finish and allowed to cure. After the concrete completely hardens, a curing membrane can be added to the hardened concrete to maintain the moisture content. A grinding tool is then used to grind away the topmost layer of concrete in order to expose the aggregates. No additional laminate or coating is necessary since the grinding process results in a smooth, watertight permanent finish desirable in pool surfaces. Further, aggregates, which are present in the original concrete mixture, can be exposed after appropriate grinding, thereby eliminating the step of applying a second layer of concrete, and allowing the pool designer to create aggregate-based design patterns on the pool surface.