Whether you’ve been admiring your old wood floor for years or you just discovered it hidden under some old carpeting, refinishing it can be a feast for the senses..Sanding a Hardwood Floor A walk behind sander has a large rotating drum that evenly removes the finish if you use the correct series of sandpaper grades and operate the sander properly. Rental stores have the three grades of sandpaper you need for successful floor refinishing co., medium, and fine..Sanding your hardwood floors takes three sessions with progressively lighter grit sandpaper. To begin, use a co grit, then a medium grit and finally a fine grit. For flat floors, use a random orbital sander. This sander is easier to handle than a drum sander and eliminates directional scratches..Proper sanding levels the floor and brings back the grain, one of the desirable attributes of a hardwood floor. Several p.es with the sanding tools will be required to achieve a smooth finish. Provide ventilation while sanding and staining..