Thermal arc spraying taking off
Fitzroy Engineering has always invested in the latest training, technology and equipment, with one recent example being the acquisition of the best thermal arc spraying equipment in the country and the training of an inspector who now holds an internationally recognised certificate in this field.
About a year ago, Fitzroy acquired an Arcspray 150-500 system to augment the balance of services the blasting and painting division offers. While still only a relatively small part of that division’s overall workload, demand for the sophisticated thermal arc spraying system is now soaring as its advantages over traditional hot dipped galvanising become more widely known.
Fitzroy’s industrial coatings manager Murray Robinson says thermal arc spraying offers significant benefits over other protection methods as the whole thermal arc spraying process is mobile.
“So coatings can be applied virtually anywhere, on site, in fact,” he adds.
And arc sprayed coatings can be tailored to suit budgets and ‘longevity targets’ by appropriate material selection and thicknesses -- typically 60-350 microns though this can be thicker. Extra thickness can be applied to isolated areas that are subject to high corrosion and/or wear rates.
Arc sprayed anodic coatings are extremely durable and will not chip off even when hit with a hammer and will still perform well even with heavy scratching. Arc spraying offers at least 20 years of protection before first maintenance is necessary and there is virtually no heat input to the substrate, he adds.
Many materials -- from aluminium, bronzes and copper to molybdenum and steels -- can be arc sprayed with no curing or drying times necessary. So the sprayed item can be handled immediately afterwards.
Thermal arc spraying also offers outstanding adhesion properties, properties that are often specified as a base layer for paint systems.
“We have had our arc spraying unit for about 12 months, we have five trained applicators, and all work is inspected by a qualified inspector who holds certification – NACE Certified Coating Inspector – Level 2 -- with the Houston-headquartered NACE International group of companies.
“While most of the division’s work is still blasting and painting, as specified by our clients, there has recently been a large increase in thermal arc spraying jobs being specified,” says Murray.
“This could even become the predominant metal spraying method as more and more people realise its many advantages; things like low heat input during spraying eliminating the risk of thermal distortion and eliminating the risk of thermal metallurgical degradation, and the process able to coat any many metals other than just zinc,” Murray adds.
“The coating material may be selected specifically for particular environments, with coating thicknesses being able to be varied from place to place to provide extra protection. The metal arc spraying process produces no residues so there are no effluent disposal problems.”