anti rust coating failure on bolts

Protect steel and other metals with anti rust coating

Anti rust coating, as the name implies, is a type of protective coating that prevents surfaces from falling prey to corrosion.  The coating acts as a barrier between a metal and its environment, increasing its durability and lifespan. The most common form of this coating in Singapore is industrial anti rust coating which is applicable on many surfaces.  Other possible anti rust paint applications include for example low pressure coating, electrostatic coating, curtain coating and automated spraying applications.

In general anti rust coating is suitable for almost any type of steel and metal, and has the following benefits:

  • Repels water & other fluids (in case of barrier coatings)
  • Fends off fungi, algae, and moss
  • Weather protection against acid rain,  salt water, ice and so on
  • Chemical resistance
  • Plus, depending on the type of anti rust paint you opt for: anti fouling, non slip or self cleaning properties

To determine the right corrosion resistant paint and application method for your project, it is important to factor in the environment and type of metal. Whether corrosion is due to moisture, chemicals, salt spray, or oxidation, corrosion resistant coatings for steel and metal can help protect the substrate from the elements.

Anti rust paint is not a single type of coating

Anti rust coating in Singapore is essentially a collective name for various types of coatings that protect a substrate from corrosion. An anti rust paint can do more than just protect from corrosion, and its multi-functional nature means you can find the exact coating you require. Corrosion is caused by a chemical reaction between a metal and its environment (water or other fluids), typically producing an oxide or a salt of the original metal. The long and the short of it is the metal is weakened, as is the structure it creates. An anti rust coating prevents direct contact between water/fluids and the steel substrate and therefore prevents the corrosion process.


Anti rust coating protects your substrate against corrosive elements

To determine the right type of anti rust paint for your project, you need to understand the environment and use of the substrate. Particularly its exposure to water, moisture, and other aggressive substances that might be present in the environment. The corrosivity of certain atmospheres has been classified and standardized by the International Organisation for Standardization. The standard divides the degree of corrosivity into 5 categories , C1 to C5, in order of increasing corrosivity. To find the right anti rust coating, you need to know how corrosive the environment will be. For example, a coating at C5M level is intended for offshore constructions which are constantly exposed to moisture, but also for small pipes that are equally exposed.

marine environment surfaces in need of anti rust coating for steel

A steel ship hull or anchor is often classified as C5 for anti rust coating.

5 categories to determine corrosion risk and suitable anti rust paint

Once you have identified your environment according to the category list below, you can identify the right coating systems for your project and the right anti corrosive paint specification to protect it for years to come. Following these guidelines will allow you to pick appropriate anti corrosion coatings for steel and other metals, allowing you to avoid overspending on unnecessary degrees of protection or simply making the wrong choice.

C1 – very low corrosion risk: Heated buildings with clean air, interiors only.
Suitable for: offices, schools, hotels, shops and other heated premises.
C2 – low corrosion risk: Unheated buildings, rural areas.
Suitable for: storage facilities, sports halls, garages, barns and other unheated buildings.
C3 – moderate corrosion risk: Buildings with high humidity, urban and industrial areas.
Suitable for: laundries, breweries, kitchens, food processing sites and other buildings with moderate humidity.
C4 – high corrosion risk: Chemical manufacturers and swimming baths, industrial and coastal areas.
Suitable for: industrial buildings, chemical plants, swimming pools, ports, and ship- and boatyards.
C5 – very high corrosion risk: Buildings with almost permanent condensation, offshore and industrial areas.
Suitable for: Water pipes and other industrial applications (C5I – industrial). Offshore and maritime constructions (C5M – marine).


3 types of corrosion resistant coatings for steel

Steel is a widely used material due to its properties. Unfortunately, immunity to corrosion is not one of them. This is because steel is simply another alloy of iron. Therefore, corrosion resistant coatings for steel are developed to prevent it from rusting. Corrosion weakens steel, reduces its conductivity and also makes it look less appealing. However, an appropriate steel anti corrosion coating can eliminate all those issues. Anti corrosion coatings for steel, stainless steel and other metals can be divided into three categories:

  1. Barrier coatings (C1 – C3) – non-porous anti corrosion coating for steel designed to prevent corrosive factors coming into contact with the substrate.
    For example: powder coating, polyurethane paint, chloro rubber paints, Teflon coatings, nano coatings.
  2. Galvanic coatings/Cathodic protection (C3 – C5) – Anti rust metal coating systems which provide a sacrificial layer. Prevent corrosion by providing a more easily corroded metal (such as zinc) to be the anode to the protected metal’s cathode. Also called the sacrificial anode, this metal will corrode instead of the protected metal.
  3. Inhibitor coatings (C1 – C4) – anti rust paint which releases a chemical which interferes with the electrolyte and stops the corrosion process.
    For example: all oil based coatings with corrosion inhibitor additives such as zinc, aluminium, zinc oxide and so on.

Apply anti rust metal coating by dipping or spraying

The two most common methods for applying a industrial grade metal anti rust coating are hot dip galvanisation and thermal (metal) spraying, you can also combine two methods for optimal results. This is called a duplex system. Let’s explain:

  1. Thermal (metal) spraying applies zinc or aluminium to a substrate by taking the metal in the form of a powder or wire and feeding it into a special spray gun. The metal is melted within the gun and can then be sprayed onto the substrate. This anti rust spray does not alloy, but instead works by coating the surface in overlapping metal platelets.
  2. Hot Dipping is the process of immersing a metal in a bath of metal, often molten zinc, in order to form a rust resistant coating. The liquid metal bonds to the substrate and forms an alloy, which is then coated in zinc as it is removed from the bath. Hot dip galvanizing uses the principle of cathodic protection, as the zinc coating acts as an anode to its substrate.
  3. Duplex system when hot dip galvanisation is used together with a topcoat of rust resistant paint or powder it is known as a Duplex System. It provides multiple types of protection and the longest-lasting results.  It is especially suitable for corrosion category C3 to C5, and is often the best anti rust coating for steel.

Anti rust spray & paint for smaller substrates like bolts & screws

For smaller substrates like bolts, screws, or do it yourself application up to category C2, painting is also an option.

Rusty bolt can be prevented with anti rust coating

Rusty bolts can be prevented with a proper anti rust coating system.

There are also small anti rust spray paint cans available for this purpose. An anti rust spray can be described as an ultra thin fluid film compound which you can spray on any steel or metal surface. In spray form it can protect for up to a year. But keep in mind that more exposed areas that are getting constant abuse from rain and salt will need spraying regularly. In paint form, more long lasting results can be accomplished depending on the corrosion resistant coating system you choose. For the best result always opt for a two component coating with corrosion inhibitor additives, for example a zinc rich epoxy coating. Most of the anti rust sprays are additionally:

  • Reducing friction for high pressure loads;
  • Impact resistant;
  • Heat resistant.

Suppliers and costs of anti rust coating in Singapore 

If you are looking for a professional company to apply the coating for you, it’s important to understand how prices are established before you request a quote. Different coating processes use different methods to calculate the cost of professional application. Hot dip galvanising prices are usually calculated by weight. The galvaniser will quote a price per tonne, and then use the weight of your steelwork after galvanising to calculate the final cost. Unlike galvanising, powder coating prices tend to be calculated by size or surface area.

Anti rust paint Singapore: Local specialists

If you want to receive a custom made quote for anti rust paint, or get in touch with anti corrosion paint manufacturers, please contact us by clicking the request a quote button below the page. Here are a few examples of local anti rust coating specialists in Singapore:

Anti rust coating CompanySPECIALISATION
Copas Coatings Pte Ltd Address: 8 Aljunied Ave 3 Oakwell Bldg (389933) SingaporeBarrier coatings, Galvanic coatings
Hempel (S) Pte Ltd Address: 25 Tuas Ave 11 S(639088) SingaporeIndustrial Anti Corrosion Products, Galvanic coatings, Cathodic protection
Amos Paints Singapore Pte Ltd Address: 196 Pandan Loop #02-24 Pantech Business Hub S (128384) Singapore Barrier coatings, Galvanic coatings, Inhibitor coatings
Zerust Singapore Pte Ltd Address: 18 Boon Lay Way #09-126 TradeHub21 S (609966) SingaporeBarrier coatings, Galvanic coatings
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