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You will find that not all manufacturers use the same grit designation. Some will use 70 instead of 50, 120 instead of 100, 220 instead of 200, etc. There are some manufacturers that also offer a 600-grit resin and some that label their abrasives as 1, 2, 3, 4, etc. It should be noted that some manufacturers produce hybrid abrasives where a combination of metal and resin is used.

The concrete would dictate at what grit a densifier would be applied. There are three types of densifiers that are most commonly used - sodium, potassium and lithium. Each manufacturer has specific directions for application that should be followed.

Just because two contractors have the same grit sequence specified, the outcomes they achieve polishing on the same concrete can be drastically different. Remember all the variables that are within the contractor's control and work with them for the best results.

Know Your Variables
There are many variables a contractor must deal with on a polished concrete project. An experienced polishing contractor who knows how to deal with these variables will have success on his or her job.

Variables within the concrete polisher's control:
Equipment

• Weight, RPMs, speed at which the machine is moving over the surface in a liner motion
• Planetary movement - active or passive
• Direction of planetary movement

Abrasives

• Configuration of the diamonds' face/tread
• Saturation of diamond grit in the bonding
• Hardness of diamond bonding
• Point at which you switch abrasives

Densifiers

• When you apply
• What type you use

Physical grinding, honing and polishing

• The degree to which the concrete surface is cut
• The level of clarity of the cut surface
• The refinement of the concrete from one grit to the next
• How well the floor is cleaned between each grit abrasive

Variables NOT within the concrete polisher's control