For cleaning, use a soft cloth or sponge with warm water and liquid detergent, soap, or Relay Spray. For severe stains, you can use kerosene, turpentine, or white spirit applied on a cloth. Rinse off residue afterward. If the Aluminium has a grain, always rub the surface in the direction of the grain. Routine clean using high pressure water to remove any food deposits, bird droppings and salt build-up. 

 For minor scratches, clean as recommended above then use a Scotch-Brite pad or stiff wire brush to restore aluminum by hand. You can use wax on the surface for a shiny appearance. To remove deeper scratches, use sandpaper to reduce the surrounding surface and so ‘remove’ the scratch. Doing this requires very fine sandpaper (at least at the end of the process) and the surface may then require a thorough polish. 

To avoid corrosion and to protect the metal, it is recommended that any exposed metal as a result of damage to the coating be repaired quickly.