Dark water spots are a nuisance. Between professional cleanings or other hardwood treatments, it's worth knowing how to manage dark water spots on your hardwood floors.
Clean spot and surrounding area with No. 2 steel wool and a wood floor cleaner or mineral spirits. Thoroughly wash the spotted area with household vinegar. Allow it to remain for three to four minutes. If the spot remains, sand with fine sandpaper, follow the grain pattern of the wood, feathering out 3 to 4 inches into the surrounding area, re-wax, and polish. If two repeated applications of vinegar do not remove the spot, apply the oxalic acid solution directly on the spot. Proportions are one ounce oxalic acid to one-quart water or a fraction thereof.
**Use recommended cleaner and buff vigorously with a clean towel. Refinishing might be necessary
