Black Spots

­ Black spots are caused by water that has penetrated the finish completely and entered the wood. They cannot be removed without damage to the finish. If the spots are on a clearly defined surface, you may be able to remove the finish from this surface only; otherwise, the entire piece of furniture will have to be stripped. When the finish has been removed, bleach the entire stained surface with a solution of oxalic acid. Then refinish as necessary.