How to Fix an Uneven Stain on Refinished Wood Floors

Load your sander with its rough sanding belt. Turn on the sander and immediately begin running it over the floor, with direction of the wood grain, taking up the old finish and digging into the wood. Push and pull the sander forward and back, working your way across the floor.

Vacuum the floor to remove the dust.

Set the medium sanding belt into the sander, and repeat the sanding process, taking up the remaining finish, including all the stain, leaving the floor bare. Vacuum the dust.

Loan the fine sanding belt into the sander and sand it again, smoothing out the surface. Vacuum well.

Brush on wood stain to the floorboards with a paint brush, starting at the far corner of the room. For Apply the stain thickly over a roughly three-by-three-foot section, let it sit on the wood for one minute, then wipe up the excess stain with rags.

Repeat, staining the floor section by section. Step back frequently to assess the look of the stain and ensure it's staying from section to section. Adjust the sit-time of the stain on the floor as needed to make it lighter or darker (less than a minute for light, more than a minute for darker). Do the whole floor.

Let the stain dry for 24 hours.

Gloss the floor by spread polyurethane onto it in a thin, even layer with a paint brush. Let the polyurethane set for six hours. Lightly sand it by hand with extra-fine sandpaper. Apply a second coat. Repeat the sanding and glossing process for a third coat. Let the final coat dry for 24 hours.