Most of scratches on concrete were usually made by the coarse metals grit 30 or grit 16.
If grit 60 cannot cover grit 30, grit 120 can only cover grit 60 scratches but can ot cover grit 30.
So the grit 30 scratches are there always but cannot be seen clearly if you don’t check carefully.
After you use the hybrid pads until grit 3000, the floor will be very glossy. The scratches will be seen clearly.
To solve this problem, if scratches area is not big, you can use hand grinder with 5, 7 inch edge polishing pads from grit 50-3000.
To avoid this problem, you should check carefully when use grit 60 metals to cover grit 30.
Let the floor grinder go through the floor 2-3 times when you grind the concrete.
After metal #60, you can use #120 metal to finish the grinding process. If metals are finished,