Chainwire fencing is wonderful stuff. It is put together through a mechanised process, it does its job economically, and once it is up it gives years of trouble-free service. Its one weakness is looks: plain galvanised chainwire is a stark grey that reminds people of cold industrialism, and it does not blend into every setting. But that grey, and how long a fence resists rust, both come down to one decision: the coating.
Every metal fence needs a coating to prevent or delay corrosion, and there are more options than most people realise. Choosing the right one for your environment is what separates a fence that lasts decades from one that rusts out early. Here is the full picture.
The coatings available
Galvanising
The classic. The wire is run through a bath of molten zinc before weaving. The zinc clings to the steel, and when it meets the air it forms zinc oxide, then zinc carbonate, a tough, corrosion-resistant layer. It comes in standard, medium and heavy thicknesses, and the choice depends on the wire's expected life, where it is exposed and cost. Galvanising is flexible and economical, which is why it is the standard on farms, orchards and general-purpose fencing. Its downside is that stark grey colour.
Powder coating
Powder coating is a colourful alternative, and it does two jobs at once: colour and a second layer of protection. It should not be confused with painting. The metal is electrically charged, then sprayed with a fine powder that clings to the oppositely charged surface. The piece is then heated so the powder melts and flows into the surface, forming a hard, durable film. Applied over galvanising, it gives a double protective layer as well as a colour.
Powder coatings come in a few types, most commonly PVC, along with polyethylene (PE) and polyurethane (PUR). PVC is the most durable and the most widely used. Because it shrugs off salt, acid and alkaline, it suits fences near chlorinated pools, coastal locations and water treatment sites.
Zinc-aluminium (ZA / Galfan)
For a step up in corrosion resistance, a zinc-aluminium coating, also called Galfan, combines zinc with around 5 to 10 percent aluminium. The wire is usually double-dipped, once in a standard galvanising bath and again in a ZA bath. It resists corrosion better than plain galvanising, which is why it is used on wire ropes, springs and demanding fencing.
ZA plus powder coating
For the harshest environments, powder coating can be added over a ZA coating to push durability and lifespan further still. This suits fences exposed to chemical fumes in industrial areas, or high-salinity coastal and seaside sites.
Stainless steel
At the top end, stainless steel uses chromium in the alloy for the longest life and the highest corrosion resistance. It costs more, and it is harder to work, so it is generally reserved for extreme environments where nothing else will hold up.
Powder coating versus hot-dip galvanising
Powder coating and hot-dip galvanising are the two most common finishes on fabricated steel fencing components, and people often ask which is better. They work very differently.
Powder coating sits on top of the steel. It is a hard, even film cured onto the surface, available in any colour, ideal where the fencing has to match a building, a school's colours or a corporate spec. But because it is a surface film, any breach, from impact, abrasion or a scratch at a cut edge or weld, exposes bare steel. In humid or coastal air, rust can start at that point and creep under the surrounding coating. A quality powder coat on steel fencing typically lasts 10 to 15 years before it needs attention.
Hot-dip galvanising bonds to the steel. The component is cleaned and dipped in molten zinc at around 450 degrees, and the zinc reacts with the steel to form alloy layers that are integral to the metal, not a film on top. Crucially, galvanising also gives cathodic protection: even if the zinc is scratched through to bare steel, the surrounding zinc corrodes first to protect the exposed metal. That self-sacrificing behaviour is why galvanised steel performs so well outdoors over decades. Its limitation is colour, it gives the familiar silver-grey unless powder coated over the top. In the same suburban environment, galvanising typically lasts 20 to 50 years before significant maintenance.
The best of both is a duplex system: galvanise first for corrosion protection, then powder coat over the top for colour, UV resistance and a second barrier. It costs more upfront but can extend service life well beyond either finish alone, which makes sense on high-value or hard-to-access installations.
Which finish for the Newcastle and Hunter environment?
The region really has two environments. Coastal and harbour-adjacent sites, from Stockton through to Swansea and around the Lake Macquarie foreshore, sit in genuinely corrosive salt air. There, galvanising is the minimum for structural steel components, and a duplex system is the better call for gates, post bases and weld-heavy fabrication. Inland Hunter Valley sites, construction compounds, logistics yards, mining support and rural properties, face less salt, so either finish can be appropriate depending on looks and budget.
For chainwire specifically, galvanising is the standard finish in both environments. The open mesh means every wire is exposed on all sides, and a surface-only coating like powder coat is impractical to apply evenly and quick to fail at the wire intersections. Hot-dip galvanising coats the entire wire including the twisted joins, which is why galvanised chainwire stays effective for decades in the field. Where colour is wanted on mesh, a PVC or powder finish over galvanising does the job.
Cost over the life of the fence
Per component, hot-dip galvanising is generally the lower upfront cost for structural steel. Powder coating varies with the colour and the complexity of the part, simple flat sections are cheap to coat, while fabricated gate frames with welds and mitred corners take more preparation. But the more useful comparison is over the fence's life. A galvanised fence that needs no maintenance for 30 years costs far less over that time than a powder-coated fence that wants a touch-up at year 12 and a recoat at year 18, especially on a long or hard-to-reach run.
The takeaway
Match the coating to the environment. For a coastal or high-humidity site, galvanise as a minimum and add powder coat over the top if you want colour. For an inland site where looks matter and exposure is moderate, powder coating is fine, just make sure cut edges and welds are sealed. And where the fence needs to last as long as possible with the least intervention, use the duplex system. Get the coating right and everything else about the fence lasts longer for it. For colour options on mesh, see black chainwire fencing.