If you want to know how to polish concrete I'll cover the basic steps it takes to grind and hone the concrete surface to get the desired degree of shine and smoothness you're looking for.
The concrete polishing process is similar to sanding wood. The difference is polishing concrete involves using diamond pads instead of sand paper.
There are many variables to consider when evaluating a concrete surface for polishing.
Is the slab level?
Are there low spots?
Are there high spots?
Is the floor cracked?
These are just a few that may play a role in the final outcome of the finished look.
There are two methods used to polish concrete, wet vs dry. See POLISHING CONCRETE METHODS for an explanation of these two processes.
The concrete polishing equipment used is a walk behind floor grinder for big jobs and a hand held grinder for small jobs and edges.
It takes many steps or passes with a grinder to finish a highly polished floor. As a general rule, the diamond grit size is doubled for each pass completed.
1. With most floors you will start with 16 - 50 grit metal bonded pads. These pads are very aggressive and will clean and even out the surface before the polishing begins.
Move the machine forward and backwards in a straight line setting over the width of the grinder with each pass.
2. Repeat this process doubling the grit size up until you reach about 60 - 100 grit size. By now you may have gone over the surface area with 2 or 3 different grit sizes depending on the condition of the floor.
3. A liquid densifier or hardener is applied to the concrete at this time to harden and strengthen the cement matrix between the aggregates. The densifier soaks into the pores of the concrete and hardens. This increases the strength, density, and impermeability of the concrete.
4. The "polishing" begins now, after densifying, you keep moving up in grit size from 100, 200, 400, 800, all the way to 3000 depending on the desired surface. I like really shiny.
After you've made the last pass the surface should have a nice sheen to it. It's time to vacuum and mop the floor to clean it and your done.
A polished concrete floor requires very little maintenance. Regular vacuuming and an occasional damp mop will keep it looking beautiful for many years. If you would like to learn how to polish concrete it would be worth the money to take a course.
The grinding machine isn't difficult to run, but knowing the grinding process like how fast to go and when to change grits requires experience for a successful job.
For more information about polished concrete check out the links below: