Water-based products to combat corrosion and rusting

31st May 2013 By: Sashnee Moodley - Senior Deputy Editor Polity and Multimedia

Coatings manufacturer Kansai Plascon has introduced three new industrial water-based products to prevent the corrosion and rusting of metal substrates.

Kansai Plascon national industrial sales executive Cassiem Narker says the company’s waterborne polyurethane topcoat is suited to high-performance applications like rolling stock and industrial tankers.

“The waterborne polyurethane has good durability and a stable pot-life profile. This means it has a slow, steady increase in viscosity after catalysing, unlike some water-based polyurethane products whose viscosity drops significantly after catalysing, making their application specialised,” he explains.

The product, which was developed after five years of extensive research, is also available in an easy-to-use 4:1 mixing ratio by volume.

The waterborne polyurethane topcoat was launched in August 2012.

“Traditionally, polyurethane is based on solvent-based formulations. Special formulating techniques were used in developing this waterborne polyurethane technology,” Narker explains.

He says the product is environment friendly, as water is used in place of a solvent in its formulation. The waterborne polyurethane topcoat is also thinned to application viscosity using water after catalysing.

“It has great resistance against weathering and marring and has low odour during application,” adds Narker.

Further, all equipment and utensils used to apply the product can be cleaned with water immediately after use.

The second product launched by Plascon in June 2012 was a waterborne primer that is easy to use and is available in 5 ℓ and 20 ℓ single packs.

“High-performance corrosion protection of metals is traditionally achieved using two component epoxy systems. This high-performance waterborne coating meets demanding corrosion-protection requirements. This single-pack waterborne system also dries fast, even at temperatures of 10 ºC,” says Narker.

He adds that it is touch-dry in 30 minutes at 23 ºC and can be overcoated with a water-based coating in two hours at the same temperature.

The primer can be overcoated with a range of finishing coats. The waterborne polyurethane is the ideal topcoat for this product as it can be used together as a coating system. It provides corrosion protection and is resistant to underfilm corrosion creep. It also offers low odour during application.

The product can also be applied without being thinned by airless spray, brush or roller, or it can be thinned for conventional spray applications.

Up to 1 000 hours of salt spray can be endured by this product at 75 µm dry film thickness.
Narker believes that this product is unique to the South African market, as it has raised the bar in terms of corrosion-protection performance from a single-pack, waterborne primer.Plascon also offers the AquaDuo Direct-to-Metal water-based coating that serves as a primer and topcoat.

It can be directly applied to prepared galvanised and mild steel, and rust inhibitors are built into the coating; therefore, no primer is needed, which saves time and money.