From industrial facilities and manufacturing hubs to residential buildings and high-end corporate headquarters all over the world, floors made from concrete, especially polished concrete, are becoming the preferred choice for contractors and their customers. In addition to reducing maintenance costs, concrete floors are durable, long lasting, environmentally sound for LEED projects, reflect light beautifully and can give the appearance of unique stonework.
Before a floor can be transformed however, the hard work of preparing an old floor for a new application must be taken care of. Not only to clean and sanitize, but to remove all built-up residues or coatings, which, if left on the surface, will impede any successful concrete polishing job. Depending upon the type of residue, the hardness of the concrete, the desired finish and the square footage of the area, grinding removes almost any coating, epoxy, glue or mastic. Between the actual grinding machine and the concrete is the diamond tooling, the real workhorse of any equipment package. Understanding how to determine the appropriate type of diamond tooling relative to the substrate you are working on, as well as the desired end result, is crucial.
Anatomy of Diamond Tooling
Definition: Diamond tooling cuts or polishes a concrete surface using one of the hardest materials on Earth: diamond grains, a distinct advantage compared to tools that use common abrasives such as corundum and silicon carbide.
Bond: In order for a grinder to use diamonds to cut, small chips of diamonds are suspended in a bond made from metal, resin, carbides, hybrid or mixed-resin (a blend of both resin and metal bonds) or polycrystalline PCD.
- Metal-bonded diamonds are ideal for removing brittle adhesives
- Carbide-bonded diamonds are ideal for removing tacky adhesives, leaving a smooth finish and no damage to concrete
- PCD-bonded diamonds are ideal for removing epoxy coatings, adhesives, leveling compounds or membranes and quite popular because they are so aggressive
To achieve the greatest productivity on hard concrete, a soft-bonded diamond needs to be used; conversely, a hard-bonded diamond needs to be used on soft concrete.
Segment: Segment refers to the raised part of the tool that holds the bond. More segments on the mounting plate means less head pressure, whereas a single segment withstands all of the head pressure.
Grit: Diamond tooling is available in various grits, indicating the size of the diamonds within the bond. The lower the number of grit, the larger the size of the diamond. The higher the number, the smaller or finer the diamond. Most concrete grinding jobs require a combination of diamond grits to achieve a desired end finish.
Knowing whether the substrate you are working on is soft, medium or hard concrete determines the correct diamond bond to use, which dramatically increases productivity. You can determine concrete hardness by conducting a Mohs Hardness Test, which ranks the hardness of all minerals on a scale of 1 to 10 from softest to hardest. Concrete falls between 4 and 8 on the Mohs scale.
Surface Prep Selections
- Removes mastic, carpet or tile adhesive, thin-set and thin-mil coatings like urethane or paint
- Uses rigid, exposed diamond-coated blades to grind stubborn coatings from concrete, creating a level floor with normal use
- Retains sharp cutting points over the life of the tool
- Designed to fit a wide variety rotary flooring machines
- Low profile design enables tool to travel over gaps in the concrete
- Simply apply water to eliminate dust and to flush debris away
- Money-saving replaceable blades
Husqvarna Pirhana PCDs
- Rids concrete of hard-to-remove coatings, adhesives and screeds
- Specially formulated grade of Pirahna PCD diamond scraper inserts ensure maximum wear and productivity
- For use on the PG machinery range in conjunction with the Redi Lock system
- Single or double quarter-round PCD with protective diamond strip
- Tools can be re-tipped once worn out
HTC Metal-Bond T-Rex Series
- Removes coatings as opposed to grinding them, including thick coatings such as paint, epoxy, varnish, acrylic, glue and screed residue
- Finer scratch pattern
- Leaves a good profile for laying down a new floor covering
- T-Rex EZchange Gold allows the user to choose the correct grinding pressure needed
Trends In Diamond Tooling
One of the hottest trends in diamond tooling today is the use of transitional diamonds or hybrid diamond tooling, which combines the deep cutting and grinding action of metal tooling with the softer polishing action of resin tooling, making the progression from grinding to polishing easier and faster. Modern contractors are also testing the use of diamond-impregnated pads, which are easier to use and tend to last longer than traditional diamond tooling.