After sitting and floating in water, aluminum pontoons can become discolored and water-streaked. This staining can be difficult to remove. Many products which remove water stains are unsafe to use on aluminum, as they are too corrosive. However, toilet bowl cleaner is a safe and effective way to remove the stains and leave the aluminum pontoon looking shiny and clean.
Spray the outside of the pontoon with a hose or pressure washer. This removes the built up dirt and dust, while also getting the aluminum wet.
Dilute 1/2 cup toilet bowl cleaner per 1 gallon of warm water in a large bucket.
Dip a large automotive sponge in the soapy water. Rub the water into the outside of the pontoon. Allow the toilet bowl cleaner to work into the surface for five to 10 minutes, depending on how stubborn or thick the stains are.
Rinse the soapy water from the pontoon with a hose. Repeat the process as needed to entirely remove the stain.
Allow the pontoon to air dry or use a towel to prevent water spots.