Concrete can be polished using wet or dry methods, but typically they use a combination of both. The wet process uses water to cool the diamond abrasives and eliminate grinding dust. Because the water reduces friction and acts as a lubricant, it increases the life of the polishing abrasives, particularly the resin-bonded disks, which can melt at high temperatures. One aspect of the wet process is the slurry, which must be contained. Crews must collect and dispose of the slurry that’s generated. We have many methods to help control, reduce and eliminate the waste slurry. When Leed points are being considered and indoor air quality is a concerned this is a preferred method.  Propane machines allow for this to be done in a safer manner.
 
Dry polishing requires no water. Instead, contractors use machines equipped with dust-containment systems that eliminate some of the dust. Typically wet grinding is used for the initial grinding steps, when more concrete is being removed. As the surface becomes smoother, and crews switch from the metal-bonded to the finer resin-bonded diamond abrasives, they generally change to dry polishing. However, some diamond manufacturers have introduced resin-bonded disks that are designed to withstand the friction and heat of both wet and dry polishing.

Certain slabs are extremely hard, concrete and aggregate strengths can exceed the abilities of dry grinding techniques. Often times wet grinding, with its increased cutting characteristics is the only reasonable alternative. While one can start the grinding process dry and, if needed change it to wet, it is generally not advisable to start grinding wet and switch to grinding dry on the same slab. The process can change from job to job, and either method will result in a beautiful and lasting shine.

Please click the article below for an OSHA fact sheet for safety information in regards to polishing concrete and crystalline silica:

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