Eco-friendly metal coating replacement for chromate

CSIRO has developed the Quench Coat coating technology to protect galvanised products from white rust.

CSIRO has developed the ‘Quench Coat’ coating technology to protect galvanised products from white rust.

White rust is the form of zinc oxide that tarnishes freshly galvanised coatings, making them look dull.

The CSIRO technology performs in a similar way to the widely used but highly toxic chromate. Australian galvanisers currently use chromate as a conversion coating on metals to protect against short-term corrosion and as a base for additional protective coatings.

CSIRO Materials Science and Engineering scientist, Dr Scott Furman, says Australian industry is keen to find an alternative to chromate.

“Quench Coat is a simple drop-in replacement for chromate in the galvanising industry,” said Dr Furman.

“Some alternatives to chromate require the use of hazardous solvents, which have occupational health and safety issues. Because Quench Coat is water-based, it has none of these disadvantages.”

The technology is designed to replace chromate in hot-dip galvanising and also works with other types of galvanising on metals such as aluminium and magnesium.

CSIRO trials found Quench Coat matched chromate in accelerated and outdoor exposure tests, is more readily paintable and has good adhesion characteristics.

Because the product does not use toxic chemicals during manufacturing, it creates a safer working environment and reduces health risks to workers.

CSIRO is seeking a coatings company to produce and distribute the technology commercially.

For more information contact Dr Scott Furman, CSIRO Materials Science & Engineering

03 9545 2787, Scott.Furman@csiro.au