Marine coatings and their best application area in a ship

Many technically incline marine professionals to wonder why they use marine coatings to paint their ship only to find rust and degradation after some time. They wonder why marine coatings cannot retain the protection of their craft. Coating professionals from Lube-point are here to the rescue. The marine coating offers both beauty and protection from environmental degradation caused by rust. A company in Nigeria lost in material value well over $2.5 million and more if the time to be wasted in reconstructing the metal structures is considered. The Lube-point Recommended Marine coatings and their best application area in a ship in this article. We are also aware that the global cost of corrosion globally is estimated to be US$2,505 billion, which is equivalent to 3.4% of the global GDP (2013). In addition, these costs typically do not include individual safety or environmental consequences. 

What are marine paint and coatings?

Marine paint and coatings are consistently used interchangeably. Marine paint and coatings are waterproof, protective layers applied to surfaces exposed to or immersed in fresh, brackish, and saltwater. They are used with boats, ships, yachts, ferries, and other watercraft and marine platforms such as offshore oil rigs.

The application of marine coatings is quite a plethora, but we will mention a few majorly applied.

The protective coating mainly used in the marine environment to protect assets like ships, yachts, tankers, vessels, and others from the salty water made of the sea are marine coatings. Marine coatings can deliver maximum protection to surfaces in which they are applied. This particular functional property makes it unique; for example, a marine coating can protect submerged materials, vessels, ships, or yachts from the degrading effects of seawater. 

Corrosion and bacterial attacks mainly occur in marine environments; hence always have a degrading effect on the metal used in sea vessels and their life span. Evidently, billions are spent annually to protect these vessels from corrosion caused by these attacks. Every shipowner needs to have a plan of action to protect their assets because the asset costs a lot of money to acquire; hence must be protected. We recommend that they implement a corrosion control strategy with proper coatings for appropriate areas of their ships. Marine coatings have unique characteristics to protect maritime vessels and other seagoing carriers above and below the waterline.

Different types of marine coatings

Marine coatings are of four types:

1. Antifouling coatings

2. Anti-corrosion coatings

3. Foul release coatings

4. Others- self-cleaning and self-polishing coating

Antifouling coatings

Antifouling coating is a specific kind of coating usually applied on the exteriors of ships or boats to stop organism growth. Some organisms can be particularly dangerous for this part of the vessel and significantly affect its sturdiness and performance. Antifouling paints This type inhibits fouling growth by producing ingredients that stop these organisms from settling. The use of this coating plays a huge role in decreasing the commercial costs of sea vessels and ultimately reduces total operating expenses for maritime industries and others.

Many top-quality antifouling coatings (such as PPG, Jotun. etc) could deliver lifetime benefits like extended dry dock intervals or decreased dry dock, which lowers maintenance expenses and harmful emissions. Apart from preventing the growth of microorganisms. Antifouling paints improve the corrosion resistance of steel structures. The most popular and available range of antifouling coatings is a linear-polishing polymer (LPP) and more advanced self-polishing copolymers (SPCs). Ship-owners and other marine operators can effectively extend the life of their vessels and other structures with the help of such coatings, it will also reduce the cost of the entire operation.

Anti-corrosion coating

The protective coating from corrosion keeps the metal components safe against degradation due to their exposure to salt, moisture, oxidation, and other environmental or industrial chemicals. Anti-corrosion coating allows for added protection of metal surfaces and acts as an obstacle to constrain the contact between chemical compounds or corrosive materials. Such paint adds non-stick performance, abrasion resistance, and chemical protection. This coating offers a high level of protection against corrosion for parts operating in exceptionally harsh environments.

An anti-corrosion policy must be taken into account right from the design phase of the vessel. Designing a ship with high-performance, anti-corrosion protection, and a low life cycle cost has consequences for the design, structure, and construction process. Essential things to keep track of for making the right choice of materials, protective means, and coatings, including paints, are the knowledge of the ship’s environment and its operating profile.

Foul-release coating

The foul release coating keeps the hull safe by providing a slippery surface for microorganism attaching. It also offers good resistance to mechanical damages to boats or ships. The fouling release coatings do not prevent fouling but lessen the grip of fouling organisms on the surface. When the water moves relative to the surface, the forces remove the attached fouling organisms.

Self-polishing coating

The self-polishing behavior of the paints is achieved through the erosion process of the polymeric binder, enabling the release of incorporated biocides at a constant rate. These paints prevent the growth of marine life and subsequently minimize corrosion on the hulls of seagoing vessels.

Marine paints and their best area of application in a ship

Marine paints’ best use is exposed and immersed into saltwater or freshwater for watercraft: these paints are waterproof and protect the submerged materials. Marine paint is used for houses, like hardwood floors, furniture, and other exterior surfaces. Different colors are available in ships, boats, ferries, yachts, submarines, etc.

Every single surface on a ship is under constant attack, from acidic cargo spillage to ordinary seawater to various unsavory microbes. Without intervention, most ships would dissolve under this corrosive bombardment and reduce their functionalities and values.

But it’s pretty simple to protect and extend the life of your vessel by using the suitable marine coatings. The ship is composed of different parts and functions making them exposed to different types of corrosion, this is why there is no single coating type that will be appropriate for all different types. 

Let’s discuss each ship area, the associated coating that will be best to apply, and why the recommendation. 

Paint for the ship Hull

Hull coatings have two primary purposes: to protect the steel from corrosion and keep the hull’s surface, especially the hull portion that contacts water, smooth and frictionless.

The coating for the protection of the hull and the boot-topping must be really touched because it takes severe punishment when docking and undocking. Vinyl and chlorinated rubber paints are commonly used here but it has been discontinued because of the high VOC levels. Breathing in high levels of VOCs can cause a number of short-term health problems, from headaches and dizziness to a runny nose and itchy eyes. Some VOCs may also cause nervous system and organ damage, according to the American Lung Association.

The preferred high-performance coating as of today is a multiple-layer high solids epoxy such as a  zinc-rich primer which has at least two epoxy coatings is perfect for boot-topping.

For the part of the hull that will contact water, you need an excellent antifouling coating; This coating keeps the hull smooth by discouraging the growth of marine life and microorganisms that can attach themselves to the hull. How important is an excellent antifouling coating? Drag resulting from a hull that is fouled increases fuel consumption by up to 40%, while also increasing air pollution.

The antifouling coating you want will depend on the asset you own; they can be significantly expensive if you blindly buy this product, however, there is great pricing from GZ Industrial supplies because they ship glocally. The way biocidal antifouling layers work is by poisoning marine organisms, and also releasing foul coatings to create a slick film that makes it difficult or impossible for organisms to latch onto the hull.

Microbes and corrosion can damage the hull of a ship.

Some advantages bring upon other disadvantages like while foul release coatings are more environmentally friendly, they also increase drag, making them counterproductive for the coating of the ship hull. Foul release coatings are always better for assets that are going to be stationary, while biocidal antifouling layers make more sense for fixed assets. This is a very important aspect that shipowners must include in their arsenal of maintenance strategies.

We should note that these coatings will be maximally effective only if the steel surfaces are properly prepared with the hull and the other sections of the boat.

Best Paint for the ship deck

The ship deck has a myriad of activities always going on in it such as wear and tear from routine deck activities, there are the activities of salty air and seawater which are considered very corrosive.

Every night the deck is also covered in salt-laden dew, which is then heated up in the daytime, compounding the problem.

One of the acceptable strategies to protect your deck according to our coating experts is a multi-step, high-grade coatings system that consists of a primer, an epoxy mid-coat, and a topcoat that is recoatable.

A zinc primer is used first to enable it to adhere to the metal deck, thereafter a high solids epoxy coating is applied that then shields the deck from corrosive substances; the epoxy polyamides or any good surface-tolerant epoxy will both work here.

Finally, a surface coating is necessary to protect the epoxy itself from deteriorating. A polyurethane topcoat shields the epoxy coating from harmful UV light, which can cause them to fade or chalk. In contrast, an additional coat of something like a glass-fiber-reinforced epoxy can protect from activities of heavy equipment within the ship. Note that Epoxies can be slippery when wet, so high-traffic areas should include non-skid additives in their coating for safety reasons, if available an epoxy floor paint is most suitable here.

A good alternative coating for the deck is a polyaspartic coating; because polyaspartic coatings are resistant to UV light and are less slippery than epoxies – great for high-traffic areas – but are more expensive overall.

Best Tank Coating for ships

Coatings for tanks are a tricky one. The ballast tanks have high potentials for corrosion because they’re constantly being flushed with seawater; making them experience an accelerated rate of corrosion, along with lots of temperature fluctuations.

The coating industry standard for ballast tank coatings is a surface-tolerant or a coal-tar epoxy. They’re resistant to seawater corrosion and compliant with the Safety of Life at Sea or (SOLAS) convention provisions regarding seawater ballast tanks. applying multiple epoxy coats can further extend your protection.

The Best coating for ship superstructure

The superstructure has many exposed areas, which gives it significant challenges. The standard is multi-layer high solids coating system (zinc primer/epoxy coat/protective topcoat) gives it excellent protection, their application can be laborious and also expensive during repairs and recoats. For this reason, people prefer acrylic or alkyd coating systems that are easy to reapply but fade much faster than a high solids coating. taking a decision here now becomes important considerations on the situation at hand and availability of the coating.

For the superstructure of the ship, it is important to also consider using an anti-rust for finishing. coating for the ship cargo and storage areas

Selecting a coating for cargo tanks is very important; this is because of the type of cargo it must carry. The paint must resist the exposure of any cargo that it is carrying, any substances released by the shipment, and the surface cleaned load after load. The recommended paint must also not contaminate any cargo that’s going to be consumed by humans.

The best coating will depend on what kind of cargo you anticipate carrying. Phenolic epoxy is one of the most versatile coatings in terms of the range of shipments it’s compatible with; bimodal epoxy is also highly versatile, with reduced absorption, but it requires lengthy post-curing. We recommend epoxy mastic coating like PITT-GUARD^® DTR Epoxy Mastic because it offers high chemical resistance for tanks handling petroleum or chemical products. The estimated cost for corrosion effects on facilities according to NACE is  $2.5 trillion, it pays to find a suitable coating for your ship. Give us an opportunity to serve you