3M Perfect-It Boat Wash is a vital to start any refinishing project with a clean surface. The 3M Perfect-It Boat Wash cleans grime, algae, dirt and other common marine contaminants from stem to stern. This Prep-Step allows for superior refinishing results. And as a professional concentrate, you only need 75ml per 10 litres of water. 3M Perfect-it Boat Washâ€™s high-suds formula is also gentle enough to clean without stripping wax.