What Is A Duplex Coating System?
A duplex coating system is a steel finishing method that combines:
- hot-dip galvanising
and - powder coating
to provide enhanced corrosion protection, improved durability, and a more attractive finish for outdoor steel products.
This combination is widely used across the construction, infrastructure, highways, manufacturing, and security industries where steel products require both:
- long-term weather protection
and - professional appearance
At Aremco Barriers, many of our steel bollards, height restriction barriers, swing gates, and perimeter security products are available with duplex coating systems for maximum outdoor durability.
How Does A Duplex Coating System Work?
The duplex coating process normally involves two stages.
Stage 1 – Hot-Dip Galvanising
The fabricated steel is immersed into molten zinc at approximately 450°C.
This creates a thick zinc coating that helps protect the steel from:
- rust
- corrosion
- moisture
- environmental exposure
The galvanised coating becomes metallurgically bonded to the steel surface, providing extremely durable long-term corrosion protection.
Stage 2 – Powder Coating
Once galvanised, the steel is prepared and powder coated in the required colour finish.
The powder coating provides:
- colour
- improved appearance
- UV resistance
- additional surface durability
- architectural finish options
Together, these two finishes create a highly durable protective system.
Why Is A Duplex Coating System Better?
The combination of galvanising and powder coating provides several advantages over using either finish individually.
Superior Corrosion Protection
The galvanised coating protects the steel underneath, while the powder coating provides an additional protective outer layer.
This significantly extends product lifespan in outdoor environments.
Improved Appearance
Powder coating allows steel products to be finished in a wide range of RAL colours and textured finishes.
Popular colours include:
- RAL 7016 Anthracite Grey
- Black
- Green
- White
- Yellow
- Red
- Blue
This makes duplex coated steel ideal for:
- commercial developments
- schools
- retail parks
- architectural projects
- public spaces
Longer Service Life
Duplex coating systems generally provide a longer service life than galvanising or powder coating alone.
The powder coating helps shield the galvanised layer from environmental exposure, helping extend overall protection.
Reduced Maintenance
Because both finishes work together, duplex coated steel products often require:
- less maintenance
- fewer repairs
- reduced repainting
- lower long-term lifecycle costs
What Products Use Duplex Coating Systems?
Duplex coating systems are commonly used on:
- security bollards
- removable bollards
- telescopic bollards
- height restriction barriers
- swing gates
- Armco barriers
- parking barriers
- perimeter fencing
- access control systems
particularly where both durability and appearance are important.
Is Duplex Coating Suitable For UK Weather?
Yes.
Duplex coating systems are extremely well suited to UK outdoor environments due to their resistance against:
- rain
- frost
- UV exposure
- pollution
- road salt
- moisture
- industrial environments
This makes them ideal for commercial, industrial, highways, and public realm applications.
What Is The Difference Between Duplex Coating And Painted Steel?
Unlike standard painted steel, duplex coating systems provide:
- thicker corrosion protection
- sacrificial zinc protection
- improved surface durability
- longer lifespan
- better resistance to chipping and corrosion
Even if the powder coated surface becomes damaged, the galvanised coating underneath continues helping protect the steel.
Common Applications For Duplex Coated Steel
Duplex coated steel is commonly used across:
- schools
- business parks
- industrial estates
- commercial premises
- highways infrastructure
- perimeter security projects
- retail developments
- public realm schemes
where both aesthetics and durability are required.
Duplex Coated Steel Products From Aremco Barriers
At Aremco Barriers, we supply a wide range of galvanised and powder coated steel products manufactured for long-term outdoor durability and professional appearance.
Our duplex coated product range includes:
- steel bollards
- removable bollards
- telescopic bollards
- height restriction barriers
- swing gates
- Armco barriers
- parking barriers
- bespoke fabricated steelwork
If you require assistance selecting the right steel finish or corrosion protection system for your project, our team will be happy to help.