How zinc protects
The reaction of the molten zinc with the steel during the hot dip galvanizing process results in a coating that is metallurgically bonded to the steel. The coating is not a simple zinc coating over the steel substrate but, rather a series of hard iron/zinc alloys that become more zinc rich towards the outer surface of the coating.
These alloys provide for an adherent coating that is harder than the underlying steel providing very good resistance against mechanical damage. The coating also thickens over corners providing excellent protection over areas that tend to be thinly coated and poorly protected using organic coatings.
Should an exposed area of steel occur, the zinc surface will preferentially corrode at a slow rate and protect the steel. This preferential protection is termed cathodic protection and, where damage is small, the protective corrosion properties of zinc will fill the exposed area arresting attack.
Finally, in addition to the barrier protection afforded, zinc protects against under- film creep (attack under the coating) should mechanical damage be so severe as to expose the underlying steel. Under-film creep is a common failure mechanism with organic coatings where rust spreads from any damaged area.
Zincfix®
On the rare occasion your galvanized steel item is damaged, Zincfix® is one of the most effective remedial steel protection solutions that can be applied on-site.
Zincfix® is an organic bound zinc rich coating containing >80% metal. It is applied to clean steel and hot dip galvanized surfaces to form an adherent anti-corrosive layer in excess of 100 microns thick. Zincfix® combines the convenience of squish pack technology with the chemistry of modern solvent free epoxies.
Download further information here or contact your Perry Metal Protection branch to purchase.
