Galvanization:the induction of twitching in frog’s legs by the application of electricity.
That’s what it meant originally. In current use, galvanization means the application
of a zinc coating using the hot-dip method where the steel passes through a bath
of molten zinc at 460 degrees Celsius. Zinc coatings prevent corrosion of the protected
metal by forming a physical barrier, and by acting as a sacrificial anode if this
barrier is damaged. When steel is withdrawn from the galvanizing bath it has a clean,
bright, shiny surface. When exposed to the atmosphere, zinc reacts with oxygen to
form zinc oxide, which further reacts with water
molecules in the air to form zinc hydroxide. Finally zinc hydroxide reacts with
carbon dioxide in the atmosphere to yield a thin, impermeable, tough, dull grey layer
of zinc carbonate which adheres extremely well to the underlying zinc, thus protecting
it from further corrosion. The finish on the plant containers shown here has been
achieved with acid bath treatments. The patina can take up to two years to become
fully stable and unless special processes are undertaken, zinc coatings should either
be painted within 48 hours of plating or after two years of weathering.
Some types of galvanised plant containers available: