Use Duragloss Marine & RV Black Streak Eliminator 581 to remove those unsightly black streaks with little and almost no effort. Black Streak Eliminate 581 is safe to use on all fibreglass-gelcoat, metal and painted surfaced. Boats, Caravans and other Recreational Vehicles commonly have dirt, mildew, grime, fuel and other contaminants run-off leaving ugly black streaks down the body or hull. Use Duragloss Black Streak Eliminator regularly to clean, and eliminate the cause of black streaks. Duragloss 581 is a professional strength cleaner, so a little goes a very long way! *How to use;* Spray directly onto area affected, allow to soak for approx 10-20 seconds and agitate if required with a soft scratch-free brush or microfibre cloth. Rinse thoroughly with water. For harder and more stubborn stains, repeat until clean. Please note: for more neglected and older stains dulling may occur if left on too long – the use of Duragloss Marine & RV Polish may be required to restore the area. For highly polished aluminium spotting may also occur, so please take care and rinse thoroughly in case of any overspray.