Wood Bleach contains oxalic acid which, when mixed with hot water, effectively bleaches unfinished or stripped wood quickly and easily. Wood Bleach is excellent for removing black water spots and tannin stains in wood. Use on all unfinished woodwork, floors, doors and more to lighten wood or match different wood colors. Savogran 10501 Wood Bleach, 12 oz. Sold as 6 Pack