Metal Arc Spray
Thermal metal spray creates a bonded metallic coating that outperforms traditional paint in high-risk, high-corrosion settings. InterGroup applies zinc, aluminium and zinc-aluminium alloy coatings to infrastructure, marine and industrial steel across New Zealand.
What is Thermal Arc Spray
Thermal metal spray (also called thermal zinc spray or metallising) melts a metal wire and sprays it onto blasted steel, building a protective metallic layer. Arc spray uses an electric arc between two wires and compressed air to atomise the molten metal onto the surface. The coating protects steel two ways: it acts as a barrier, and zinc corrodes in preference to the steel underneath (sacrificial protection).
Zinc, aluminium or zinc-aluminium?
- Thermal zinc: the most common choice, giving sacrificial protection in most atmospheric environments.
- Thermal aluminium: widely used in marine and offshore settings.
- Zinc-aluminium alloy (85/15): combines the properties of both, suited to demanding conditions.
We select the wire and thickness to match your environment and required service life.
Thermal zinc spray vs hot-dip galvanising
Both protect steel with zinc, but they suit different jobs. Thermal spray can coat items too large for a galvanising bath, can be applied without heat distortion, and copes well with edges and welds. It works on fabricated and existing steelwork where dipping isn’t practical.
Our metal spray process
- Abrasive blast preparation to the required surface standard
- Thermal arc spray of zinc, aluminium or alloy to the specified thickness
- Sealing to extend system life
- Compatible topcoat where colour or added protection is needed (a duplex system)
For restricted-access areas where thermal spray isn’t practical, we offer zinc-rich coating solutions.
Applied in our facilities or on site
We apply thermal metal spray in our blast and paint facilities located in Kawarau, New Plymouth and Christchurch, and can depending on the asset and access.
What we protect
- Structural steel
- Marine and offshore steelwork
- Tanks and pipework
- Trailers and fabricated components
- Industrial and highly exposed steelwork
