Galvanised vs Powder Coated Steel: Which Finish Is Best? | Aremco Barriers

When buying a steel barrier, gate or bollard, one of the decisions you'll need to make is which finish to choose.

Two of the most common options are hot dip galvanising and powder coating. You may also have the option of combining the two by having the steel galvanised first and then powder coated.

But what's the difference, and which is best for your application?

At Aremco Barriers, we manufacture steel barriers, gates, bollards and vehicle access-control products for sites throughout the UK. In this guide, we'll explain the differences between galvanised and powder-coated steel and the reasons you might choose one finish over another.

What Is Galvanised Steel?

Galvanising is a process used to protect steel against corrosion.

With hot dip galvanising, the fabricated steel product is immersed in molten zinc. This creates a protective zinc coating over the steel, including areas that can be difficult to protect using a conventional painted finish.

The main purpose of galvanising isn't appearance – it is corrosion protection.

This makes galvanised steel particularly suitable for products that will spend their working life outdoors and exposed to the British weather.

At Aremco, where specified, our hot dip galvanised products are galvanised in accordance with BS EN ISO 1461.

What Does Galvanised Steel Look Like?

Freshly galvanised steel typically has a bright silver or grey appearance.

The exact appearance can vary.

Some areas may appear brighter or duller than others, and the surface can develop the familiar crystalline or "spangled" appearance associated with galvanised steel.

Over time, the finish will naturally weather and usually become a more uniform matt grey.

This variation is normal and doesn't necessarily indicate a problem with the galvanised coating.

If appearance and a particular colour are important, powder coating may be more suitable.

What Is Powder Coating?

Powder coating is a finishing process where a dry powder is applied to prepared metal and then cured to produce a continuous coating.

One of its major advantages is the range of colours available.

Rather than being limited to the silver-grey appearance of galvanised steel, powder-coated gates, barriers and bollards can be supplied in a variety of RAL colours.

This can be particularly useful where a product needs to:

• Match existing site furniture
• Match company branding
• Be highly visible
• Contrast with its surroundings
• Meet an architect's or customer's specification

Yellow, black, white, red, blue and green are among the colours frequently requested for barriers and vehicle access products.

Is Galvanising Better Than Powder Coating?

Neither finish is automatically "better".

They perform different jobs.

Galvanising is primarily selected for corrosion protection.

Powder coating is often selected for colour and appearance while also providing a protective coating to the steel.

The best choice therefore depends on the product, its location and what you expect from the finish.

When Should I Choose Galvanised Steel?

Galvanising is a particularly good option for outdoor products where long-term corrosion protection is a priority.

It can be suitable for:

• Swing gates
• Bollards
• Armco barriers
• Height restriction barriers
• Industrial barriers
• External steelwork
• Car park equipment
• Vehicle access-control products

It is also a practical choice where the appearance of the product is less important than durability.

For industrial sites, service yards and similar environments, the silver-grey appearance of galvanised steel is often perfectly acceptable.

When Should I Choose Powder Coating?

Powder coating is worth considering where colour or appearance is particularly important.

For example, a yellow height restriction barrier is much easier for approaching drivers to see than an unpainted steel structure.

Similarly, black and white, yellow and black or other contrasting finishes can help make bollards and barriers more noticeable.

Powder coating may also be specified to complement:

• Existing fencing
• Building colours
• Corporate branding
• Other street furniture
• Site safety colour schemes

Aremco can supply powder-coated products in a range of RAL colours depending on the particular product and specification.

Can Steel Be Galvanised AND Powder Coated?

Yes.

This is often described as a duplex coating system.

The steel is galvanised first to provide corrosion protection and is then prepared and powder coated to provide the required colour and finished appearance.

This gives you the benefits of the zinc coating beneath the coloured finish.

For outdoor barriers, gates and bollards where both corrosion protection and appearance are important, galvanising followed by powder coating can be an excellent option.

Why Does Galvanised and Powder-Coated Steel Cost More?

There are effectively two finishing processes involved.

The product first needs to go through the galvanising process and then requires suitable preparation before powder coating.

This naturally involves more processing than choosing either galvanising or powder coating alone.

However, for customers who want the corrosion protection offered by galvanising together with a specific colour, the additional cost can be worthwhile.

Does Powder Coating Stop Steel From Rusting?

Powder coating provides a protective barrier between the steel and the environment, but the coating needs to remain intact.

Like any coated finish, it can be damaged.

For example, a gate or bollard may be:

• Scratched
• Chipped
• Struck by a vehicle
• Damaged during installation
• Subjected to general wear

If damage exposes the bare steel underneath, corrosion may eventually begin at the exposed area.

This is one reason why galvanising beneath a powder-coated finish can be beneficial for external steel products.

Can Galvanised Steel Rust?

Galvanising is designed to protect the underlying steel against corrosion, but it shouldn't be regarded as making a steel product indestructible.

The zinc coating itself changes over time as it protects the steel.

Environmental conditions, exposure, damage and the thickness of the coating can all influence its service life.

A galvanised product can also require attention if it suffers significant physical damage.

Which Finish Is Best for Coastal Areas?

Coastal and highly corrosive environments deserve additional consideration because salt and moisture can increase the rate of corrosion.

If a barrier, gate or bollard is going to be installed in a particularly aggressive environment, tell the manufacturer when requesting a quotation.

The location and environmental conditions can then be considered as part of the specification rather than simply selecting a finish based on appearance.

What About Products Installed Into the Ground?

Root-fixed barriers, gates and bollards have sections installed below ground, so correct installation is particularly important.

The product finish is only one part of protecting the installation.

Foundations, drainage, concrete and local ground conditions can all affect the long-term performance of external steelwork.

Any damaged protective coating should also be addressed during installation rather than simply being buried or concreted over.

What RAL Colour Should I Choose?

RAL is a widely used colour-matching system that allows a particular colour to be specified consistently.

Some colours commonly associated with barriers and access-control equipment include:

• RAL 1021 – Rape Yellow
• RAL 1023 – Traffic Yellow
• RAL 9005 – Jet Black
• RAL 9016 – Traffic White
• RAL 3020 – Traffic Red
• RAL 6005 – Moss Green
• RAL 5002 – Ultramarine Blue
• RAL 5003 – Sapphire Blue

However, you don't have to choose one of these colours.

If you have a particular RAL colour requirement, let us know when requesting your quotation and we can advise whether it is available for the product concerned.

Which Finish Is Best for a Height Restriction Barrier?

Visibility is an important consideration with height restriction barriers.

For this reason, powder-coated finishes – particularly highly visible colours such as yellow – are commonly selected.

Where additional corrosion protection is required, galvanising followed by powder coating may be considered depending on the particular barrier design and specification.

The height restriction sign itself should also be clearly visible to approaching drivers.

Which Finish Is Best for a Swing Gate?

This depends largely on where the gate is being installed.

A galvanised swing gate can be an excellent practical choice for industrial and commercial sites where corrosion protection is the priority.

A powder-coated gate may be preferred where a particular colour or appearance is required.

If both are important, a galvanised and powder-coated finish may be appropriate.

Which Finish Is Best for Bollards?

Again, it depends on the application.

Galvanised bollards can work well in industrial environments, while powder-coated bollards can provide much greater visibility.

Contrasting bands and reflective material can also make bollards easier for drivers to see.

For parking areas and vehicle routes, visibility should always be considered alongside appearance.

Will the Colour on My Screen Match the Finished Product Exactly?

Not necessarily.

Computer monitors, tablets and mobile phones can display colours differently, so a RAL colour viewed on a screen shouldn't always be treated as an exact representation of the finished coating.

Lighting conditions can also change how a colour appears.

If an exact colour match is particularly important to your project, this should be discussed before manufacture.

Do Galvanised and Powder-Coated Products Need Maintenance?

Yes.

No external steel product should simply be installed and forgotten indefinitely.

Periodic inspection is sensible regardless of the finish.

Look for:

• Scratches and chips
• Impact damage
• Areas of corrosion
• Damaged fixings
• Wear around hinges and moving components
• Damage caused during operation
• Deterioration around ground level

Problems are generally much easier to address when identified early.

Galvanised, Powder Coated or Both – A Quick Guide

Choose galvanised if:
Long-term corrosion protection is the main priority, and a silver-grey industrial appearance is acceptable.

Choose powder coated if:
Colour, visibility and appearance are particularly important.

Choose galvanised then powder coated if:
You want the corrosion protection of galvanising together with a coloured finished appearance.

There can, however, be product-specific reasons why a particular finishing method isn't suitable, so it is always worth checking before ordering.

Need Help Choosing a Finish?

If you're unsure whether your barrier, gate or bollard should be galvanised, powder coated, or galvanised and then powder coated, speak to Aremco Barriers.

Tell us what product you require, where it will be installed, the environment it will be exposed to and your preferred colour.

We can then advise on the finishing options available for that particular product.

Aremco Barriers manufactures steel barriers, gates, bollards and manual vehicle access-control products for commercial, industrial, public-sector and private applications throughout the UK.

Please note: Prices displayed on the Aremco Barriers website are guide prices only. Contact us for a quotation based on your specific requirements.

Frequently Asked Questions

Is galvanised steel better than powder-coated steel?

Not necessarily. Galvanising is primarily used for corrosion protection, while powder coating provides a coloured protective finish. The best option depends on the application.

Can you powder coat galvanised steel?

Yes. Galvanised steel can be suitably prepared and powder coated, providing both the protection of galvanising and a coloured finish.

What colour is galvanised steel?

Galvanised steel normally has a silver or grey appearance. Its appearance can vary when newly galvanised and generally becomes duller and more uniform as it weathers.

Can I choose the RAL colour of my barrier or gate?

For products available with a powder-coated finish, a range of RAL colours can be specified. Availability should be confirmed when requesting a quotation.

Is galvanising suitable for outdoor gates and barriers?

Yes. Hot dip galvanising is widely used to provide corrosion protection to external steelwork.

Does powder coating require maintenance?

It should be periodically inspected for scratches, chips, impact damage or other deterioration. Damage should be addressed before corrosion of exposed steel develops.

Can all Aremco products be galvanised and then powder coated?

Not necessarily. The construction and operation of some products can affect which finishing processes are suitable. Aremco can advise on the available finish for the particular product being ordered.