In general coating removal is best achieved with coarse diamonds

However there are special products that can spectacularly increase the productivity of your floor grinder known as PCD scrapers

These scraper cupwheels pictured below contain small "teeth" that shave off the coatings and are most efficient when used for very thick or self levelling coatings.

Polycrystalline Diamond (PCD) scraper wheels for rapid removal of thick coatings

After using the PCD scrapers the floor usually needs diamond grInding because the scrapers are not meant to grind the concrete, they are only used for coating removal.

Coarse diamonds will cut through coatings better than fine diamond sizes which tend to clog up with the coating material.

There should be enough bite in the size of the diamond to penetrate the coating and score it so a 30/40 grit is recommended and for thicker coatings, grits of down to 10 can be used successfully, but they leave visible score marks on the surface.

To successfully remove coatings diamond grinding must also remove some of the surface of the concrete floor so it is important to have the right bond hardness for the hardness of the concrete. See Grinding Hard Concrete for more information about segment bonds.

Coating stickiness

Acrylics, "DIY paving paints" and some glues become sticky with the heat generated by the floor grinder, especially when multiple coats have been applied over the years. These coatings soften and stick to the segments instead of grinding away cleanly.

Most epoxies and urethanes have set hard and grind away in a similar manner to concrete.

Scraping instead of grinding

If the coating is a problem to remove with a diamond cupwheel try coarser diamonds, or try a PCD scraper disc or take smaller bites into the coating each time.

Sometimes a long handled scraper can be useful to scrape away most of the coating before diamond grinding.

PCD scraper discs will be most successful on hard concrete as will soft bond, very-coarse diamonds down to 10 grit.

Coarse diamond 30/40 grit with the right bond will be better on soft to medium hardness concrete.

Next page "Angle Grinders"