Industrial Coatings for Marine Applications | New Guard Coatings

Protective Marine Coatings for Steel & Industrial Assets

Marine environments are among the most demanding environments for protective coatings. Constant exposure to moisture, salt, humidity and changing weather conditions can accelerate corrosion and deterioration of exposed steel and other suitable substrates.

From marine steelwork and vessels to port infrastructure, tanks, equipment and fabricated components, selecting the correct coating system is essential for protecting assets in marine environments.

New Guard Coatings supplies industrial coating solutions for marine and coastal applications across the UK, including anti-corrosion primers, protective coatings and durable topcoats.

The correct system will depend on the substrate, level of exposure, surface preparation, required durability and specific conditions of the application.

Marine Protective Coatings

Marine coatings are used to protect suitable surfaces and structures exposed to demanding coastal and marine conditions.

Applications can include:

Marine steelwork
Ships and vessels
Port infrastructure
Harbour structures
Steel platforms
Marine equipment
Storage tanks
Pipework
Fabricated steelwork
Coastal industrial structures

The coating system should be selected according to the conditions the asset will experience.

External marine steelwork, for example, may have significantly different requirements from equipment located within a sheltered or enclosed environment.

Explore Anti-Corrosion Coatings →

Why Marine Environments Cause Corrosion

Steel is particularly vulnerable to corrosion when exposed to moisture and oxygen. Marine environments can increase the challenge because of the presence of salt and high humidity.

Salt contamination can contribute to corrosion and can make effective surface preparation and coating selection particularly important.

Marine assets may also experience:

Salt spray
High humidity
Rain
Condensation
UV exposure
Temperature changes
Abrasion
Mechanical impact
General weathering

A suitable protective coating system helps create a barrier between the substrate and its surrounding environment.

Corrosion Protection for Marine Steel

Steel is widely used throughout marine infrastructure because of its strength and versatility.

However, exposed steel requires suitable protection to help reduce corrosion and extend the useful life of the asset.

Marine steel coating applications can include:

Structural steel
Ship components
Harbour steelwork
Marine platforms
Port infrastructure
Steel walkways
Railings and supports
Fabricated steel components

The required coating system depends on the specific environment and exposure.

Where steel is exposed to direct marine conditions, the coating specification should take the expected corrosivity of the environment into account.

Explore Marine Anti-Corrosion Coatings →

Saltwater & Salt Spray Exposure

Salt is one of the key considerations when protecting marine steelwork.

Salt deposits can remain on exposed surfaces and contribute to corrosion when combined with moisture.

Marine and coastal coating systems should therefore be selected with the expected exposure conditions in mind.

Consider:

Direct saltwater exposure
Salt spray
Coastal atmosphere
Humidity
Splash zones
Tidal exposure
Atmospheric contamination

Where a surface is exposed to immersion or repeated wetting, the coating requirements can differ significantly from those for atmospheric exposure.

Always check the manufacturer's technical information to confirm whether a product is suitable for the intended environment.

Marine Primers & Anti-Corrosion Primers

Primers form an important part of many marine protective coating systems.

A suitable primer provides the foundation for subsequent coats and can contribute to corrosion protection and adhesion to the prepared substrate.

Marine primer selection should consider:

Substrate
Surface preparation
Environmental exposure
Corrosivity
Intended topcoat
Required durability
Application conditions

The primer and topcoat should be compatible and specified as part of a complete coating system.

Explore Industrial Primers →

Marine Topcoats

The topcoat provides the final protective layer of the coating system and can contribute to both durability and appearance.

Depending on the application, marine topcoats may need to provide resistance to:

Weathering
Moisture
UV exposure
Salt spray
Corrosion
Abrasion
General industrial wear

The appropriate topcoat will depend on the environment and the performance requirements of the project.

For marine and coastal applications, colour and finish may also be important considerations, particularly on visible infrastructure and equipment.

Surface Preparation for Marine Coatings

Surface preparation is critical when coating steel in marine environments.

Salt, corrosion, oil, grease, dirt and existing failing coatings can all interfere with coating adhesion and performance.

Before coating, inspect the substrate for:

Rust
Corrosion
Salt contamination
Oil and grease
Dirt
Dust
Existing coatings
Loose material
Moisture
Surface defects

Preparation may include:

Cleaning
Degreasing
Mechanical preparation
Power-tool cleaning
Abrasive blasting

The required preparation method and standard should be determined according to the substrate and coating specification.

Particular attention should be given to removing contamination before coating.

Read our Surface Preparation Guide →

Coating Systems for Marine Steel

Marine steelwork will often require a multi-coat protective system.

A typical system may consist of:

Surface Preparation → Primer → Intermediate Coat → Topcoat

The exact system will depend on:

Environmental exposure
Corrosivity
Substrate
Surface preparation
Required durability
Application conditions
Project specification

A complete system should be considered rather than selecting individual products without checking compatibility.

Where a project specifies a particular coating thickness or corrosion category, the complete system should be assessed against the relevant technical documentation.

ISO 12944 & Marine Corrosion Protection

ISO 12944 is an important reference when considering protective paint systems for steel structures.

The standard provides a framework for assessing environmental corrosivity and the durability required from a coating system.

Marine and coastal environments can present elevated corrosion risks, particularly where steel is exposed to salt spray, high humidity or other aggressive atmospheric conditions.

The specific corrosivity category applicable to a project should be established according to the actual environment.

Where ISO 12944 is included within a project specification, the proposed coating system should be checked against the relevant manufacturer's technical documentation.

Explore ISO 12944 Protective Coatings →

Marine Coatings for Ports & Harbour Infrastructure

Ports and harbours contain a wide range of steel and industrial assets that can be exposed to demanding marine conditions.

Potential applications include:

Steel structures
Walkways
Platforms
Handrails
Pipework
Equipment
Storage areas
Loading infrastructure
Fabricated steelwork

Coating requirements will vary depending on whether the asset is exposed to atmospheric conditions, splash zones or immersion.

The appropriate coating system should therefore be selected according to the specific exposure.

Marine Equipment & Machinery Coatings

Marine equipment can experience moisture, salt, abrasion and general industrial wear.

Suitable protective coatings can be considered for:

Machinery
Metal equipment
Pumps
Fabricated components
Equipment frames
Industrial plant

Where machinery or equipment operates in a marine environment, the coating system should be suitable for both the substrate and the surrounding conditions.

Explore Industrial Coatings for Machinery →

Choosing a Marine Coating

There is no single marine coating suitable for every application.

Before selecting a system, consider the following.

1. What is the substrate?

Determine whether the surface is steel, another metal, concrete or another suitable material.

2. What level of marine exposure will it experience?

Consider whether the asset is:

Coastal
Exposed to salt spray
Near the sea
In a splash zone
Subject to immersion
Fully exposed to weather

3. What contaminants are present?

Salt, oil, grease and other contaminants should be considered during preparation.

4. What corrosion protection is required?

The environmental exposure and required durability should influence the coating system.

5. Is abrasion a consideration?

Marine structures and equipment may experience impact, mechanical wear and abrasion.

6. What preparation is possible?

The existing condition of the substrate will determine the preparation required.

7. What application conditions are available?

Temperature, humidity, ventilation and surface temperature can all influence coating application and curing.

Application & Drying

Marine coatings should be applied according to the manufacturer's technical requirements.

Before application, check:

Surface preparation requirements
Mixing instructions
Application method
Recommended film thickness
Temperature limits
Humidity
Surface temperature
Recoat intervals
Drying times
Curing requirements

Coatings may be applied by brush, roller or spray depending on the product.

Marine environments can present additional challenges during application because of humidity, condensation and changing weather conditions.

The substrate and surrounding conditions should meet the product's specified requirements before application begins.

Maintaining Marine Coatings

Regular inspection is an important part of maintaining protective coating systems in marine environments.

Inspect coated surfaces for:

Rust
Peeling
Flaking
Blistering
Cracking
Mechanical damage
Exposed steel
Salt contamination
General coating deterioration

Areas of coating damage should be assessed to determine the appropriate maintenance approach.

Early identification of deterioration can help prevent small areas of damage developing into more extensive coating problems.

Common Marine Coating Problems

Corrosion beneath the coating

Inadequate preparation, remaining contamination or moisture reaching the substrate can contribute to corrosion.

Peeling or flaking

Poor surface preparation, contamination or coating incompatibility can affect adhesion.

Blistering

Moisture and unsuitable application conditions can contribute to blistering.

Salt contamination

Residual salt contamination can interfere with coating adhesion and contribute to corrosion.

Mechanical damage

Impact and abrasion can damage the protective coating and expose the underlying substrate.

Understanding the cause of coating deterioration is important before carrying out repairs.

Frequently Asked Questions

What is the best coating for marine steel?

There is no single coating suitable for every marine application. The correct system depends on the substrate, level of exposure, surface preparation and required durability.

What coating protects steel from saltwater?

Suitable anti-corrosion coating systems can help protect steel from marine exposure. The coating must be selected according to whether the surface experiences atmospheric exposure, salt spray, splash or immersion.

Can industrial coatings be used in coastal environments?

Yes, suitable industrial coatings can be used for compatible coastal applications. The product should be selected according to the environmental exposure and manufacturer's technical recommendations.

How do you prepare steel for marine painting?

Preparation can involve cleaning, removal of corrosion and mechanical or abrasive preparation. Salt, oil, grease and other contaminants should be addressed before coating.

Does marine steel need a primer?

Many protective marine coating systems incorporate a primer as part of a multi-coat system. The correct primer depends on the substrate and specified coating system.

Can marine coatings be used underwater?

Some specialist coating systems are designed for immersion applications, but not every marine coating is suitable for underwater use. The manufacturer's technical documentation should be checked before specification.

What is ISO 12944?

ISO 12944 provides guidance for corrosion protection of steel structures using protective paint systems, including consideration of environmental corrosivity and coating durability.

How long do marine coatings last?

There is no universal service life. Performance depends on the coating system, environmental exposure, preparation, application, maintenance and operating conditions.

Protect Your Marine Steel & Equipment

Marine environments can place significant demands on protective coating systems.

Salt, moisture, humidity, corrosion and mechanical exposure all need to be considered when selecting and applying a coating.

Correct surface preparation, an appropriate primer and a compatible protective topcoat can help provide durable protection for suitable marine steelwork, equipment and infrastructure.

New Guard Coatings provides industrial coating solutions and technical information for marine and coastal applications across the UK.