How to Choose the Right Equipment for Grinding and Polishing

In our last issue, we introduced the idea of concrete polishing as a potential new revenue stream for rental businesses looking to break into this burgeoning market. While it’s true the majority of concrete contractors currently serving this market own their own machinery, there are tools and systems available to assist smaller contractors and even DIYers in trying their hand at polishing concrete.

There’s no doubt this market is not for everyone. Some of the equipment requires a significant investment, it’s not easily transported and it requires expensive tooling and a certain expertise to achieve the desired effect. That being said, with enough knowledge and the right frame of mind, serving the concrete polishing market could open up profit potential for rental businesses that wish to pursue it.

There are several factors to take into consideration when selecting concrete grinding equipment for your rental inventory, among them the equipment’s power requirements, weight, motor size, overall size, working dimensions and direction or directions the abrasives rotate. Following are some of the key selection factors, according to Jim Cuviello, owner of Cuviello Concrete in Stevensville, MD and one of the founding members of the Concrete Polishing Association of America.

Power requirements. Equipment is either powered by cord electric, battery electric or propane, and in some cases hydraulic-driven motors are used. With propane power there are no cords and no electrical requirements other than the battery used for starting the machine. Electrical requirements for cord electric equipment are typically 110-volt single-phase, 220-volt single-phase or three-phase, and 460-volt three-phase. Some 220-volt pieces of equipment allow you to run them single- or three-phase. Amperage requirements can range as low as 20 amps and as high as 60 amps.

Weight. Walk-behind equipment ranges in weight from 110 pounds to over 2,000 pounds before optional weights are applied. Ride-on equipment can weigh over 13,000 pounds. Equipment weight is important from a transportation point of view, but more important is the actual weight or head pressure over the abrasives.

Motor size. Motors range from 1 hp on a small, single-head rotary machine to 40 hp on a walk-behind machine with a multi-rotary head. There are three variables that affect the amount of power required for a machine to efficiently operate — how much contact area there is between the abrasives and the concrete surface, the grit designation being used, and the weight of the machine. These variables contribute to friction between the abrasive and concrete. The higher the friction, the more power required to drive the abrasives.

Overall dimensional size. You can find equipment small enough to fit in the back of a small hatchback and equipment so large it will only fit on a flat-bed tractor trailer. Equipment comes in all shapes and sizes. Some break down into multiple pieces for easier transportation and some are all one piece.

Working dimensions. This is defined as the overall area of the abrasives effect when the machine is running. Equipment working dimensions can range from square and 14 inches to round and 15 inches to 98 inches with multiple planetary heads.

Push, propel or ride on. Some machines are designed to be pushed, pulled or moved side to side while others are propelled with motor-driven wheels or come as ride-on units.

Belt/chain, gear or direct drive. The rotating heads of the machine are most often driven by a main or centralized motor that uses a belt or chain in conjunction with a pulley system. Some equipment eliminates all belts or chains and uses a gear system. Small, single rotating head machines are usually driven directly from the motor.

Abrasives drive. There are machines that have a large fixed single-rotating head that could measure 15 to 20 inches, fixed dual-rotating heads that are positioned side by side, machines that have two to eight rotating heads that intertwine in a gear-like fashion whose working width is up to 56 inches, and then there is planetary equipment where one large head rotates in one direction in addition to smaller satellite heads that rotate in the opposite or same direction.