Painting the Forth Rail Bridge, just outside Edinburgh, was traditionally the job that never came to an end.
Since its completion in 1890, the red coat on the 1.5 mile-long crossing has been reapplied many times to protect the steel of its cantilever structure from a highly corrosive mix of salt water, sea mists and high winds.
The Sisyphean undertaking even coined a local expression for any never-ending task being “like painting the Forth Bridge”.
But that idiom was put to rest in 2011, as the scaffolding that had surrounded the three enormous diamond-shaped spans for a decade was finally taken down.
A £130m investment by the bridge’s owner, Network Rail, should mean that no brush strokes will be needed for at least another 20 years.
This was thanks to a specialist coating treatment, consisting of a triple layer of new “glass flake” epoxy paint, made by Leighs Paints of Bolton, Greater Manchester. The formula creates a chemical bond that keeps moisture out, providing a virtually impenetrable layer that protects the bridge’s steelwork from the Scottish weather.
Leighs Paints now trades as the UK-based protective and marine coatings division of Sherwin-Williams, after being taken over by the world’s third-largest manufacturer of coatings five years ago. This brought the 150-year-old business under the wing of a Fortune 500 group with a history of similar vintage and annual sales of more than $11bn.
Under its new guise, the division, which employs 230 people in the UK, continues its focus on safeguarding critical infrastructure in harsh environments. It is a winner in the innovation category in this year’s awards for another industrial coating similar to that used on the Forth Rail Bridge.
The Dura-Plate 301W epoxy product is designed to prevent corrosion on steel structures in industrial installations such as offshore oil and gas rigs, refineries and petrochemical plants, as well as on bridges and other infrastructure.
At a time when energy companies are cutting costs in response to low oil prices, Sherwin-Williams says it can create savings by reducing the time needed for applying protective coatings on industrial installations.
Traditional coatings don’t always adhere to the steelwork in those extreme conditions
What distinguishes Dura-Plate 301W from rival coatings is that it combines surface and humidity tolerance with low temperature curing, according to Nick Ball, regional marketing director for Sherwin-Williams’ protective and marine coatings division.
In practice, this means it can be applied in extreme temperatures and on rough surfaces even when wet. The company says the closest competitor products manage to meet just two out of these three challenges.
The formulation of the coating allows it to be painted over partially prepared rusted surfaces in damp conditions and at cold temperatures, says Mr Ball.
“That in itself removes the need for extensive surface preparation of the steelwork, as it’s a paint for steel,” he adds.
“Traditional coatings don’t always adhere to the steelwork in those extreme conditions. We’ve developed this coating that overcomes that.”
This means that clients can paint in winter periods in conditions that would otherwise be too inhospitable. For operators of oil and gas facilities, lost maintenance time during those cold months could be a problem of the past, Sherwin-Williams says.
Dura-Plate 301W was originally launched to supply shipyards in China that build large offshore vessels that store hydrocarbons before they are transferred to a tanker. But over the past 12 months, Sherwin-Williams has rolled it out to UK and European markets.
One customer is Centrica, the UK energy supplier that powers around 11m homes and businesses through its British Gas brand. It required a new external coating for the condensate pipework and associated valves that service its gasfields in and around Morecambe Bay in north-west England.
Mr Ball says that the product reduced non-productive painting time by around 70 per cent.
Other endorsers include DNV, the American Bureau of Shipping and Lloyd’s Register, which set standards for ships and offshore structures, as well as Network Rail.
Developed by members of a 40-strong research and development team at the company’s manufacturing facility in Bolton, the new coating builds upon an existing product line from a Portuguese business acquired by Sherwin-Williams.
“[The group] is focused on bringing customers product they need for the future. That very much drove the research team in looking at unmet customer needs,” says Mr Ball.
Although most of Sherwin-Williams’ revenues come from North and South America, the company is attempting to increase its specialist business-to-business segment outside the Americas with a focus on regions such as Asia. Products such as Dura-Plate 301W play into this strategy, says Mr Ball.
“We’ve demonstrated rapid sales growth globally [and] we have really high hopes,” says Mr Ball.