The Billion-Dollar Scratch: Why Your Galvanised Steel Isn’t as Protected as You Think – And What You Can Do About It

Fun Fact #1: The amount of steel produced worldwide each year is 1,890 million tonnes – equivalent to 27,000 aircraft carriers rolling off a production line every single year. 

Cost of Corrosion 

Some estimates place the annual cost of steel corrosion in Australia as high as $78 billion annually*. Steel corrodes because oxygen reacts with iron (the main component of steel). The reaction produces rust. That’s why the tangle of metal in a scrap yard often appears reddish brown and flaky.

Galvanisation Stops the ‘Rot’ 

Galvanisation is steel's bulletproof vest – and this is why so much steel is galvanised. 

Fun fact #2: The global galvanised steel market was worth USD$174 billion in 2022 and is projected to reach USD$248 billion by 2032**. 

The Galvanisation Game 

The process involves dipping steel or iron into a tank of molten zinc (at a toasty 450°C). “Hot dip” galvanisation, as it is known, creates a chemical bond that shields the underlying metal from moisture and oxygen – the dynamic duo of destruction when it comes to steel. 

Anyone working with raw (ungalvanised) steel can achieve a similar level of protection by painting or spraying on a layer of zinc-rich paint. In both instances, the zinc layer isn't just a physical barrier. It's sacrificial, meaning it corrodes before the steel does. That’s pretty noble of the zinc.  

But Guess What: Even Galvanised Steel Corrodes

Once galvanised steel has been damaged – perhaps it was drilled, bent, bashed with a hammer, or it is just worn out – its protective armour is a bit like the cracked hull of a submarine. And the moment that zinc coating gets compromised, your countdown to corrosion begins. 

Every bolt hole drilled. Every cut edge. Every scratch from transport or impact. Each one is an open invitation for rust to start partying. 

And yet, some fabricators and maintenance crews leave these vulnerable spots open to the elements, essentially giving corrosion a VIP pass to the metal beneath. 

Not All Zinc-Rich Coatings Are Created Equal

Active zinc-rich coatings “heal” damaged steel, recreating the protective chemical bond that keeps the bullet proof vest intact.  

When recommending solutions, here's what separates the players from the pretenders: 

• Active zinc content: Premium coatings contain 92-95% zinc in the dry film, creating that same sacrificial protection as hot-dip galvanisation. Cheaper options might have just 65-75%, leaving your steel vulnerable even after application. 

• The binding system: This is crucial. Cheaper zinc coatings often get brittle and can sometimes chip and flake, exposing the steel they’re supposed to protect. Higher grade coatings deliver a more durable bond with steel, providing superior UV protection, weatherability, and chemical resistance. 

• Application window: Premium coatings can be applied in a wider range of temperatures and humidity levels – and often dry faster. 

  
  

Bottom Line 

Corrosion costs big time. 

The math is simple: spend a few dollars per square foot now on quality zinc-rich coating protection, or hundreds of dollars per square foot down the line on replacement. Keep steel's bulletproof vest intact with Galmet's premium zinc-rich coatings. Our solutions contain 98.5% pure zinc and over 92% metallic zinc in the dry film, protecting both galvanised and ungalvanised steel for the long term. Whether your customers are managing a large industrial project or simply need advice on the right zinc-rich coating to protect their steel assets, Galmet is your best bet against corrosion's costly appetite. 

Contact Galmet for top-notch rust protection and advice. Call 1800 000 945