Cold Galvanising Coatings
Cold galvanising gives structural steel and ironwork the same sacrificial zinc protection as hot-dip galvanising, without the dip tank. Applied by brush, roller or spray, a cold galvanising coating lays down a zinc-rich film that corrodes in place of the metal beneath it, stopping rust before it starts and halting rust creep where the surface is scratched or damaged.
It is the go-to solution for on-site work, welded joints, repairs to existing galvanised surfaces, and any steelwork that cannot practically be sent away for hot-dip treatment.
What is cold galvanising?
Cold galvanising is the application of a high zinc-content coating (typically 92 percent or more zinc in the dried film) directly onto clean ferrous metal. The zinc protects the steel electrochemically: in corrosive conditions the zinc reacts in preference to the iron, sacrificing itself and sealing minor breaks in the coating with insoluble zinc corrosion products. The result is long-term galvanic protection that behaves much like traditional galvanising but can be applied anywhere, any time.
Where cold galvanising is used
- Structural steelwork, beams, columns and fabrications
- Welded joints and in-situ welding repairs, where hot-dip galvanising has been burned off
- Touch-up and repair of damaged hot-dip galvanised surfaces
- Gates, railings, fencing and balustrades
- Agricultural and construction plant and machinery
- Iron pipework, guttering and downpipes
Cold galvanising vs hot-dip galvanising
Hot-dip galvanising is done in a factory dip tank and suits new, transportable steel. Cold galvanising is applied on site with simple tools, which makes it the practical choice for repairs, welded connections, awkward geometry and anything already installed. Used as a primer, a cold galvanising coating can also sit under a decorative or chemical-resistant topcoat for extra durability.