If an abrasive cost seems too good to be true, it probably is. Don’t base your purchasing decision on price. Quality manufacturers will have products with properly dispersed grit in the abrasive bond, proper grading of the grit particulate and quality particulate that won’t easily fracture or crush.
There are several forms of abrasives. Abrasive material and bonding may be sprayed onto a nylon pad; these products are used for maintenance and light restoration. Others resemble a brush where the material is molded onto fingers and are good for deep cleaning of new concrete and light preparation for a sealer. Nylon pad and brush abrasives should not be used to mechanically process concrete to a polished finish where overhead clarity of reflection and maximum durability are desired.
Abrasives that use felt and drops of resin are good for light honing and polishing after using fully bonded abrasives. Others use molded material attached to a nylon pad, but the most popular are various sizes of larger, fully bonded abrasives such as pucks, terrazzo plugs, trapezoid and trapezoid-style segments made of metal, resin, ceramic or a combination of material called hybrids. These abrasives are used for all phases of the concrete polishing process including grinding, honing and polishing and will provide maximum overhead clarity of reflection and durability.
Diamond abrasives are designed to mechanically abrade the surface. There are three levels of abrasion: grinding, honing and polishing. Grinding uses abrasives up to 50 grit; honing uses abrasives from 100 to 400; polishing uses abrasives from 800 to 3,000.
All grits create peaks and valleys. As you move up in grits, these peaks and valleys get smaller and closer together. The higher the grit, the smaller the peaks and valleys and the easier they are to remove from one grit abrasive to the next. When diamond abrasives are used properly, you will achieve a surface that, on a microscopic level, will reflect light in a perfectly organized manner. This is where you obtain depth and clarity of reflection, also called distinction of image. Any remaining abrasions, scratches or imperfections will cause the light to refract back in an obscured, unorganized manner.
Each grit is designed to not only replace the abrasion/scratch pattern of the previous grit, but to continue on and fully refine its own abrasion/scratch pattern. Consequently, skipping a grit will leave abrasion/scratch patterns that never get removed from the surface. The more refined a floor is and the higher you go in grits, the more wear resistant it becomes because on a microscopic level there are fewer large, unsupported weak peaks to wear down or for an object to catch and tear creating a scratch. A floor that has ben fully refined and brought to a grit level of 1,500 and higher has many well-supported microscopic peaks and very shallow valleys to create a highly durable surface.
Understanding abrasives will allow you to provide a better product in a more efficient manner and give you the know how to effectively work with all the various types of concrete you encounter in the field.