Industrial coatings for steel structures

Industrial coatings for steel structures

Owners and operators of high-value assets need to understand the cost implications of ignoring the effects of corrosion that poses a threat to all infrastructure through the degradation of structures such as buildings, roads, bridges, pipelines and towers. The economic impact of corrosion represents an annual cost of many billions of dollars to the economy.

Some of the advantages of planning for corrosion control and mitigation at the design phase include extending the life of an asset—thus making it more profitable—and reducing maintenance time and costs thereby increasing an asset’s utilisation.

According to Director of Napier Sandblasting (NSB) in New Zealand, Craig Ross, some construction contractors sought to save money on infrastructure projects by using substandard coatings with the result that some buildings, towers and bridges are already showing signs of fatigue and distress.

“While the majority of the shoddy coatings applicators have gone, many of their structures already require remediation,” he said. “Luckily changes in regulations and better enforcement of standards means that new designs should have a much longer operational life.”

Coatings consultant at Remedy Asset Protection, Justin Rigby, added that steel structures within industrial facilities are usually located in ‘aggressive’ environments.

“Owners of offshore platforms or dock cranes exposed to the marine environment cannot afford for corrosion to degrade their assets,” he said.

Ross added that even relatively non-reactive stainless steel requires protection in certain situations.

“NSB does a lot of work in the hide tanning industry and other really severe environments, generally where acid attack or abrasion is an issue,” he said.

Cathodic protection is one technology that can be used to impress a current into a structure to alter the surface reactive characteristics of a metal to minimise corrosion.

According to Rigby, it is important that a protective coating project is carefully planned. Protective coatings projects are usually unsuccessful for relatively simple reasons. Planners often do not fully comprehend the technical complexity of many coatings projects, especially if the coating is to be applied to an existing steel structure; even more so if the site is in a remote location. As a consequence, they fail to invest the time and resources to manage it effectively which results in substantial cost implications when things go wrong.
Protective coatings are not just paint. Coatings are engineered products that undergo rigorous testing and refinement to provide specific properties that will protect a structure from its service environment.

“A simplistic analogy would be that a structure is plastic coated,” Rigby said.

There is a wide selection of coating products available to the market so it is essential that the appropriate coatings system is chosen. There is no single product that meets every coating situation so during the planning of a project, a compromise may need to be made and not to be fooled by ‘one size fits all’ claims made by some manufacturers.