Chromate coatings are produced on zinc by immersing the cleaned metal for a few seconds in sodium dichromate solution (e.g., 200g/liter) acidified with sulfuric acid (e.g., 8mL/liter) at room temperature and then rinsing and drying. A zinc chromate surface is produced that imparts a slight yellow colour and that protects the metal against spotting and staining by condensed moisture. It also increases the life of zinc to a modest degree on exposure to the atmosphere. Similar coatings have been recommended for Zn–Al coatings and for cadmium coatings on steel.