If you have a large pool, then start with a floor sander. A floor sander looks similar to a vacuum cleaner, except it has an abrasive surface on the base of the head. This is a simple push-behind tool with a long handle. For quick sand jobs, use a belt sander. A belt sander has a rotating pad over which you place a piece of sandpaper. This tool quickly grinds away at your gunite.
For small jobs, you can also use grinders. An angle grinder has a fast rotating blade that is only partially exposed. The other half is hidden with a crescent-moon shaped metal piece. This tool works well for grinding down angles, edges and ends of items. It usually has two handles to help you better control the movement of it and to decrease the amount of vibrations that you feel. You can use this tool for overhead grinding.
Another type of small grinder is the 7-inch hand grinder. The blade of this grinder sits flat, and you rub it along the surface that you want to smooth out. This tool is mainly for floor grinding, and it spins very fast. The hand grinder is heavier than the angle grinder, and it can cause arm strain after a while.
The largest type of grinder is the walk-behind, which is another type of floor grinder. If you have a large pool, use this grinder. This grinder works similar to the floor sander, except that is more aggressive, and it will break up large chucks of exposed gunite. This grinder has different grinding wheels that move in different directions, eliminating the need to make multiple passes. The tool will completely grind an area in a single pass.
For the edges of your pool, use either a hand or a walking edger since both of these tools smooth out rough sections along your pool lip. The main difference between these tools is that you attach the walking edger to a pole, and you operate the hand edger with your hand.