If you’re using a rotary floor grinder to grind and polish concrete, it’s important you use an “s-curve” while operating it rather than simply pushing the grinder in a forward motion. In the video below, you’ll see how we do this using our Prep/Master 3030 Floor Grinder as well as the results you get if you don’t use the side-to-side motion. To learn a bit more in-depth, read the article below to better understand how rotary grinders work.

How Do Rotary Floor Grinders Work?

Rotary floor grinders rely on gears to move the heads with half rotating in one direction and the other half of the grinding heads moving in the other. For example, on the Prep/Master 3030, two of the grinding heads move clockwise, while the other two grinding heads move counter-clockwise.

As the grinding heads rotate, the tooling cuts an overlapping path down the center of the machine’s cutting area, creating a noticeably deeper cut when grinding and polishing. If you move in a straight path forward and backward, you will create “cornrows” in your concrete – deeper lines cut straight down into your concrete in an obvious pattern.

Instead of moving the grinder forwards and backward, the manufacturer of the concrete grinder will recommend you move in a side-to-side pattern. We find the best results come from moving left to right and back, keeping the machine at a 20-degree angle from the machine while progressing forward and backward in a smooth, controlled movement.

How to Perform an S-Curve in Concrete

The only time it’s recommended you move in a straight path forward or backward is when you have to grind concrete along an edge. To prevent deeper lines from being cut into the concrete, you’ll want to move forward a few feet, then move the grinder out to the side from the wall or edge, bringing it back in the smooth, side-to-side pattern to smooth out any uneven cuts.

Is a Rotary Floor Grinder Right for You?

While rotary floor grinders require more care during use to avoid cornrows, they have a greater head weight than planetary grinders. This allows the machine to cut through heavy coatings like mastic, epoxy, and multiple layers of paint while getting faster results when polishing a slab.

Get a Quote on a Floor Grinder Today

If you need a concrete grinder to add to your equipment inventory, we have a wide variety to choose from and can help you select the right option for your business. Call us today at  +1 (815) 941-4800 or fill out the form below for a free quote or to learn more.