Cabot? Wood brightener is formulated specifically to remove unsightly discoloration of wood caused by tannin bleed in extractive-prone wood types suchas cedar and redwood. It also removes nail and metal rust stains. This product can be used on all painted, stained and unfinished wood surfaces. Plus, when used on weathered wood, Cabot? wood brightener brings back the rich, new wood look. Cabot wood brightener is not a paint or stain remover. It will, however, remove paint or stain on an unsound surface.