Metal spraying using flame spraying equipment is an alternative method of coating items with zinc.
To create the molten particles, a heat source, a spray material and an atomisation/projection method are required.
Upon contact, the particles flatten onto the surface, freeze and mechanically bond, firstly onto the roughened substrate and then onto each other as the coating thickness is increased.
As the heat energy in the molten particles is small relative to the size of the sprayed item, the process imparts very little heat to the substrate.
Unlike the galvanising process, because the temperature increase of the coated parts is minimal (rarely above 100°C), heat distortion is not normally experienced. This is a major advantage over hot-dipped galvanising.
Metal spraying is a superior substrate to galvanising when paint or decorative coatings need to be applied.
Metal spraying produces a uniform, even thickness of coating whereas with galvanising, the thickness of the application varies and is difficult for the galvaniser to control.
It is common for the galvanising plater to melt wax onto the surface of the molten zinc bath to reduce the toxic zinc vapour fumes. This wax substance is often deposited onto the parts when they exit the zinc bath and is not removed by conventional power washing methods resulting in extra cleaning processes.
Metal spraying eliminates this process, and also eliminates any de-burring (fettling), a regular labour intensive requirement of galvanised products.
Compared with galvanising, metal spraying is a far more environmentally friendly process with no inherent toxic waste problems.
Surface Industries Ltd. is an ISO 9001 certfied company and can provide certificates of conformity for its metal sprayed items, a requirement for most high spec. long lasting durable work.
Hot dip galvanising steel is limited to corrosion protection using zinc, whereas metal spraying can also use, amongst other materials, aluminium and its alloys, which is much more resistant to corrosion.