To bleach and brighten wood, dilute chlorine bleach with water, and add it to a garden pump sprayer. Wet the wood with a hose, and then spray it with the bleach. Rinse the bleach after 5 minutes. To remove unwanted colors, use a solution of water and sodium hypochlorite bleach.
Use plastic drop clothes to protect any surfaces around the wood before you begin to bleach it. In a large bucket, pour 1 gallon of water and 1 quart of chlorine bleach. Stir the mixture, and pour it into a pump sprayer. Do not use a power sprayer, because the force may splinter the wood.
Wet down the wood with a liberal layer of the bleach, and allow it to soak in for five minutes. Use a garden hose to rinse the wood thoroughly. Reapply the bleach solution as needed. For tough mildew or mold stains, scrub the wood with a stiff brush after applying the bleach.
For unwanted colors on wood, use sodium hypochlorite bleach, available from swimming pool suppliers. Mix the bleach with water, using only enough for one application. Use a paintbrush to apply the bleach to the wood, wait for it to dry, and then apply it again. Sanding may be necessary if two application do not remove the color.