Step 5 grind the floor.
How to grind and stain concrete floors.
After several passes over the concrete floor with the 40 grit metal bond tool repeat the process with a finer 80 grit and 150 grit metal bond tool.
In this process the floor is cleaned using a minimum of two metal bond diamonds to cut the surface removing minor coatings and surface dirt.
If you have grease or oil on the floor you will need to use a degreaser or stain prep for concrete floors.
Make sure you protect any doorframes and walls with painters tape.
Concrete grinding staining and sealing is a great economical alternative to the full 10 step mechanical polish service.
This will remove the most stubborn remnants of most penetrating stains like oil and grease.
It is also a longer term floor type when compared to topical polish.
Since the concrete is old and you may not know for sure if any type of oils grease and thin petroleum products have ever been spilled on the concrete we suggest degreasing the concrete regardless.
When rough grinding begin from one side and grind from west to east across the entire concrete floor.
Learn how to prep your concrete for staining here.
Note that different parts of concrete will absorb stain differently.
If the floor still looks stained or patchy hire a floor grinder to grind away a thin layer from the surface of the concrete.
Floors and counter tops created with concrete can be stained to any shade or color desired adding warmth to the space for relatively little money.
Be sure to overlap the grinding pass as close to the previous grinding pass as possible.
Before applying any stain you ll need to grind and ready the surface.