SEAL ONCE CLEAR WATERPROOFER and Wood Sealer protects and stabilizes wood against water damage and decay. The water based formula uses proprietary materials to form a flexible breathable barrier by coating the wood fibers at the cellular level. This allows wood to age naturally without decay and can be used to preserve old or new wood, extending its natural life. It is non-film forming and will not alter the natural beauty of the wood. This preserves the integrity of the wood by inhibiting rot, mold and mildew growth and helps to eliminate warping and cupping. This forms a flexible breathable barrier that allows the wood to expand and contract and for water vapor to escape. The advanced technology allows it to penetrate and bond to the cellular structure of the wood, forming a superior barrier below the surface to protect from the inside out. Product goes on milky white and dries clear.