From offshore structures to commercial buildings, MIO has a role to play.

What is MIO and how does it work?

MIO stands for micaceous iron oxide, a pigment that is added to coatings to increase corrosion resistance. The flake-shaped pigment has a lamellar (or multi-layered) structure.

Compared to the spherical shape pigments commonly used in non-MIO coatings, the flake shape of the MIO pigment enhances barrier protection. The flakes form overlapping layers in the film to create a ‘tortuous path’ for liquids, making it harder for moisture to penetrate the substrate.

Raw MIO is processed to form the pigment into finer particles suitable for use in paints and coatings whilst still maintaining the flat, plate-like nature of the particles. This results in a multitude of flat, shiny surfaces that act like tiny UV-resistant mirrors. They reflect UV light away from the substrate, protecting the resin from degradation. It's this MIO protection that gives steel its attractive 'sparkle' in bright sunshine.

Key benefits of MIO coatings

In summary, MIO coatings deliver excellent corrosion protection and long-term durability by:

• forming a tough barrier against moisture ingress
• reflecting light away, protecting the substrate from UV penetration
• protecting the substrate from chalking

In some formulations MIO can also contribute to abrasion resistance of the coating.

Which MIO coating is right for my project?

Choosing the correct resin system to combine with MIO must be carefully considered in relation to the environment and expected service life. Our technical sales specialists can provide a tailored specification leveraging MIO.

The following Dulux® Protective Coatings contain a high level of MIO:

• Dulux® Durebild® STE MIO: A two pack epoxy, this self-priming coating is an excellent maintenance coating but can also be used for new work as an intermediate or topcoat.
• Dulux® Duremax® GPE MIO: This high performance epoxy protects steel in severe environments such as chemical plants, offshore platforms, refineries, ship loaders and coal wash plants.
• Dulux® Ferreko® No. 3: This two pack epoxy protects steel structures in aggressive marine and industrial atmospheres. It offers high abrasion resistance. Applications include wharf superstructures, ship loaders, bridges, hoppers, conveyors, silos and storage tanks.
• Dulux® Ferreko® No. 6: A high build, single pack, chlorinated rubber finish delivering long-term protection of bridges, tankage and other steel structures in coastal marine environments.
• Dulux® Ferreko® 810 (formerly known as Ferrodor 810): This single pack alkyd enamel is suitable for the catchment of drinking water.
• Dulux® Weathermax® HBR MIO: A versatile, high build, recoatable polyurethane topcoat, the addition of MIO means this coating can withstand extreme UV exposure. It offers excellent gloss and colour retention during extended service periods in severe industrial and marine environments.

Colours

The natural colour of MIO pigment is a dark, charcoal grey. Some MIO coatings also contain aluminium flake (another lamellar pigment) to lighten the colour.

Dulux Protective Coatings' MIO coatings are available in Natural Grey and Mid Grey (also known as 'Bridge Grey'). In some coatings, the lighter Enoch Grey is also available. You can request MIO colour samples by completing this order form.

MIO coatings in action

Dulux Protective Coatings' MIO solutions have been used on buildings and assets all over Australia. Here are some great examples of MIO in action:

• At the Library at the Dock, our Victorian team worked with the architect to deliver a low sheen finish with Weathermax® HBR MIO.
• In a high-use public space, the steel structures in Sydney's Paddington Reservoir Gardens received a tough 'heritage' finish with our alkyd enamel Ferreko® 810.
• In a C4 corrosivity environment on the Cairns waterfront, these steel pergolas are protected from the sun and saltwater, thanks to Duremax® GPE MIO.
• The structural steel supporting Melbourne's West Gate Bridge is coated with Durebild® STE MIO and Weathermax® HBR MIO. Read the story and watch the video.
• Before a colourful topcoat, Duremax® GPE MIO delivered a protective intermediate coat for the Kids' Bridge at Perth Children’s Hospital.
• A three-coat system protects the light towers illuminating Sydney Cricket Ground, including Durebild® STE MIO and topcoat Weathermax® HBR MIO.
• The subtle sparkle in Ferreko® No. 3 enhances the spectacular multicoloured lighting effect at night on these uniquely-shaped Sydney light poles.
• Zincanode 304 (superseded by Durezinc i90) and Ferreko No.3 created a long lasting, protective finish at Perth's Edith Cowan University. Read the story or find out more about the specification.

To find out more, explore our MIO coatings range or read our technical note. You can also submit an enquiry or call our team via the Contact Us page.