Unappealing black spots can easily be formed on oak wood floors.
Oak wood naturally contains a very high amount of tannic acid. The spots are formed when the wood is exposed to metal and moisture, e.g. a wet glass or leaky vase, as this triggers a chemical reaction (acid/water).
Spray WOCA Tannin Spot Neutralizer evenly on the stain directly from the bottle. Leave to dissolve for approx. 30-60 minutes.
Wipe with cloth wrung in lukewarm water.
The surface must be completely dry.
Apply the original surface finish, e.g. oil, wax or soap, to re-establish the protection of the surface.
Wipe off all excess oil using a lint-free cotton cloth.