#1 Deck Wood Stain Stripper is a biodegradable, ready-to-use liquid that quickly removes worn finishes to restore wood surfaces. Stains and varnishes are removed along with collected dirt, mold, mildew and mill glaze. This product is step 1 of a 3 step system. #1 Deck Wood Stain Stripper removes most oil and latex based finishes including: clear film-forming varnishes, polyurethanes, and semitransparent stains. Limitations: #1 Deck Wood Stain Stripper is not designed to strip paint or other film forming surface coatings. To use, simply apply the product a damp surface using a pump-up garden type sprayer, or a car wash type brush. Allow it to set for 15-25 minutes, then scrub if necessary using a stiff bristle brush, and rinse. Using a pressure washer to rinse this product will eliminate any need for scrubbing, however particular care should be taken with a pressure washer to avoid damaging the wood. After rinsing, use #1 Deck Wood Brightener to neutralize the surface and open the pores of the wood so the stain can absorb properly into the wood.