Metal-sprayed zinc, like other zinc coatings, offers excellent corrosion resistance. There are several advantages to choosing Zinc Metal Spraying over other galvanising techniques. Very large structures can be accommodated, and the work can be carried out on-site. There is no possibility of distortion, as can sometimes happen to hot-dipped items. For highly corrosive environments, an extra thick coating can be applied.
Zinc sprayed coatings provide an excellent base for painting and as it is a slightly porous coating it should be sealed or painted to be most effective. Epoxy and vinyl-based paints are very effective and they can be over-coated with a polyurethane or vinyl top coat.
Metal spraying in terms of the SABS specification can be used as a touch-up to repair damaged hot-dip galvanised coatings.
Zinc spraying is limited to the exterior of tubular items. It is recommended that hollow structures be sealed to avoid corrosion on the inside.
The steel surface has to be grit blasted first to ensure good adhesion and the zinc metal coating is then applied, either by flame spraying or arc spraying, in accordance with SABS ISO 2063: 1991.