Concrete is often ground down to obtain a glass-like smooth finish. There are various tools used for grinding concrete. The floor grinder is used to grind and smooth large concrete floors; the right-angle grinder is used to grind and smooth corners and concrete countertops; the belt sander is used to grind countertops and small floors and the orbital sander is used to place a fine, smooth finish on already ground countertops.
The floor concrete grinder resembles a commercial floor polisher. It has a round base of 24 to 36 inches. A round rotating disc inside the base holds polishing stones of various grits for grinding concrete. The base is attached to a 4-foot handle with lever controls that turn the rotating base on and off. The polishing stones are manufactured in 60-to-300-grit textures, with the 60-grit stones used for grinding coarse concrete and the 300-grit being used for polishing the concrete.
The right-angle grinder is used as a hand-held device. It has a rotating disc of 6 to 8 inches on the end of the grinder housing. The grinder is fitted with sanding papers ranging from 60 grit, which is used to even out concrete floor corners and countertops, to 120 grit, which is used to smooth the concrete into a polished finish. This grinder, however, is often used in conjunction with small amounts of water sprinkled on the surface of the concrete to prevent dust.
The belt grinder is used strictly for removing and grinding large amounts of concrete. These grinders are also hand-held. However, they are fitted with 60-grit sanding belts that spin at high speed. This grinder is mobile but still effective in smoothing rough, uneven concrete before polishing with a fine grit grinding paper. Countertops and small floors benefit from this tool the most. Additionally, grinding oil or water should be used to prevent dust.
Hand-held Orbital Grinder
The orbital sander is used to polish off already-ground concrete surfaces. This tool is handheld with a 4-inch orbiting disc that holds 80- and 120-grit papers. This tool is fitted with a side bag for trapping concrete dust. The orbital hand grinder should be used in conjunction with polishing oils or water in order to obtain a glass-like finish on the surface of the concrete.