Armoda’s portable accommodation modules and technical buildings are built to handle the extreme marine environments where our customers operate. The first line of defense against the constant presence of saltwater and weather is the paint systems the units are covered by. These paint systems ensure our units can provide a long, productive service life in the harsh marine environment. Two central paint systems are utilized in the marine industry: the three-coat marine paint system and the standard ISO paint system. In this article, we will cover what each of these systems entails and compare them. 

ISO Standard Paint System

The ISO standard paint system refers to the ISO 12944 standard, which provides guidelines for the corrosion protection of steel structures by protective paint systems. This standard is widely recognized and has become the global standard for corrosion control, replacing regional standards. It is helpful for asset owners who have a maintenance schedule, as it offers a standardized approach for selecting coating systems and verifying their suitability for specific purposes.

The ISO 12944 standard is comprehensive, covering various aspects of paint systems, including:

• Design considerations
• Types of surface and surface preparation
• Protective paint systems
• Laboratory performance test methods
• Execution and supervision of paintwork
• Development of specifications for new work and maintenance

The standard utilizes different coating systems based on the environment's corrosivity and the intended durability. It has eight parts, each addressing a specific area of paint system specification. For example, it classifies environments according to their corrosivity and provides guidelines for selecting the durability of the coating system, ranging from low (2 to 5 years) to high (more than 15 years).  

The typical paint system outlined in the ISO 12944 standard includes a primer and a topcoat. The primer serves as the first line of defense against corrosion, while the topcoat provides the desired aesthetic finish and additional protection against environmental factors.

The ISO standard paint system is a methodical approach to protecting steel structures from corrosion. It is a critical resource for ensuring the longevity and integrity of assets exposed to environmental conditions, like offshore vessels and facilities.

Three-Coat Marine Paint System

The three-coat marine paint system is designed to provide a high level of protection for marine vessels and equipment operating in harsh environments. It consists of a primary coat, an intermediate coat, and a topcoat. This system offers protection against atmospheric corrosion, especially in marine environments, and the additional layer provides improved durability and longevity compared to standard two-coat systems, which typically include only a primer and a topcoat.

Primary Coat

The primary coat forms the initial layer of protection. It is often a zinc-rich primer, providing security to the vessel's steel structure. The primer's zinc acts similarly to galvanized metals and creates a layer that protects the metals underneath from the elements.

Intermediate Coat

The intermediate coat usually consists of an epoxy that acts as a barrier to protect the steel and the primary coat from the elements. This layer is essential for its barrier protection capabilities, offering a dense, cross-linked chemical structure resistant to penetration.

Top Coat

The top coat is typically an aliphatic polyurethane that protects the underlying layers from UV radiation and gives the unit its final appearance. Each layer plays a critical role in extending the operating life of portable accommodation modules and technical buildings operating in the marine environment.
The three-coat marine paint system is a comprehensive approach to protecting portable accommodation modules and technical buildings, offering durability and longevity. 

Comparison: ISO Standard Paint System vs Three-Coat Marine Paint System

The three-coat marine paint system is a more specialized system for marine applications, offering a higher level of protection with its additional intermediate coat. While highly adaptable to various environments, the ISO standard provides a more general approach to corrosion protection, allowing for customization based on specific needs and environmental factors.

Both systems aim to extend the service life of steel structures and reduce maintenance costs. Still, the choice between them would depend on the project's specific requirements, including the environmental conditions and the desired longevity of the protective coating. The three-coat system might be preferred for marine vessels or structures exposed to severe marine conditions, while the ISO standard offers a broader range of options suitable for various industries and applications.

Armoda provides portable accommodation modules and technical buildings for customers operating in various marine environments. We work closely with our customers to ensure we provide the right paint system on their modules to meet the demands of their specific projects. If you have any questions about paint systems, contact Armoda today. We have utilized these systems across our newly built custom projects and fleet of rental units. If you’d like to learn more about the standards and certifications of offshore modules and buildings, read our previous article on the differences between DNV 2.7-1 and DNV 2.7-2.