PH Crack It is designed to release siexed and corroded parsts by shock freezing. Spray slowly onto and around seized component, taking care to catch any excess spray with a rag or suitably absordent cloth. The freeze action breaks the corrosion seal and allows the penetrant to reach the corroded area, releasing the seized items in 1 - 2 minutes. Crack It also helps to prevent future corrosion. Crack It is harmless to most skins and is completely bio-degradable.