Osmo Tannin Spot Remover 250ml

Removes the black marks that appear on oak when water or metal reaches the tannin in the timber - the ring under a wet pan, or a stain around a screw head. It treats the discolouration rather than sanding it out.

Oak is high in tannin, and tannin reacts with iron and moisture to produce a blue-black stain that goes deeper than the oil. Sanding often just spreads it.

Apply to the affected area, let it work, rinse and dry, then re-oil the patch.