This is one of the finest available wood bleaching agents. Use it to lighten dark streaks and colorations in wood so it will stain to a uniform color. It's also an effective rust and stain remover that works to remove many water stains, chemical stains and dirt where milder bleaching agents fail. It's not as harsh as the two-part bleaches and results in a more even color when bleaching smaller surfaces. With Oxalic Acid, wood will retain more of its original character. It comes in powder form as dry crystals and must be mixed in hot water. Use only on bare wood. 16 oz. box.