Protect steel with anti rust paint for metal
Anti rust paint for metal acts as a barrier between a metal and its environment, increasing its durability and lifespan. The estimated global cost of metal corrosion damage is billions of ringgits. The good news is, a lot of this loss can be prevented by being proactive, and choosing the right anti rust coating from the start.
To determine the right anti corrosion coating 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, anti rust coating for steel and metal can help protect the substrate from the elements.
In this article we take a close look at anti rust paint for metal; what it is and how it works, how to determine the best anti rust coatings and which products are available in Malaysia.
Anti rust paint for metal has more properties than corrosion prevention
Anti corrosion coating is essentially a collective name for various types of coatings that protect a substrate from corrosion. An anti corrosion 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.
In general anti corrosion 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 types of anti corrosive paints you opt for: anti fouling, non slip or self cleaning properties
Assessing corrosivity takes you closer to the best anti rust coating
To determine the right types of anti corrosive paints 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 standardised 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 paint for metal, 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.
- 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).
Once you have identified your environment, you can identify the right anti rust treatment for your project and the right anti rust coating specification to protect it for years to come. Following these guidelines will allow you to pick appropriate anti-corrosion coatings, allowing you to avoid overspending on unnecessary degrees of protection or simply making the wrong choice.
The three types of anti rust paint for metal
Anti corrosion coating types can be divided into three categories:
- Barrier coatings (C1 – C3) – non-porous anti rust coatings designed to prevent corrosive factors coming into contact with the substrate.
For example: powder coating, polyurethane paint, chloro rubber paints, Teflon coatings, nano coatings.
- Inhibitor coatings (C1 – C4) – anti rust treatment which releases a chemical that interferes with the electrolyte and stops the corrosion process.
For example: all oil based coatings with corrosion inhibitor additives such as zinc, aluminum, zinc oxide and so on.
- Galvanic coatings/Cathodic protection (C3 – C5) – metal-rich anti rust coating for steel which provide a sacrificial layer. Prevents 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.
Consider the type of corrosion when choosing anti corrosion coatings
The environment is not the only factor affecting the choice of anti corrosion coatings for steel; also the type of corrosion the surface is likely to experience has influence on the suitable coatings. Here below you can find a table outlining the different types of corrosion, as well as which coatings are used to combat the specific types.
|CORROSION TYPE||EXPLANATION||Anti corrosion coating solution|
|General attack||Also called uniform attack corrosion, the most common form of corrosion. Hence the name. It causes the object to be entirely exposed to the rust.||Barrier and inhibitor coatings, cathodic protection|
|Galvanic||Triggered when two metals of different electrode potentials come in contact with each other in presence of an electrolyte such as saltwater. As a result metal ion flow from the more active material to the less active one speeding up the corroding of the more active metal.||Barrier coating, cathodic protection|
|Pitting||Occurs when a hole forms in the metal. It occurs when a tiny part of the metal loses its protective layer, and becomes exposed to corrosive factors. May be difficult to detect because small size of the holes.||Inhibitor coating, cathodic protection|
|Crevice||Similar to pitting corrosion. Because corrosion happens at a specific location.||Minimising the tight spaces in design and applying barrier or inhibitor coatings or cathodic protection|
Find anti rust paint for metal products and services in Malaysia
Here is a selection of products on the market to give you a rough guide as to the price of anti corrosion paint. Keep in mind that for categories C4 and C5 it is not recommended to apply the anti corrosion coating yourself. Please search out a specialist in that case.
|PRODUCT||Anti corrosion coating TYPE||Corrosion Category|
|Jotun Jotamastic 90||Barrier coating: Epoxy coating for above and below water, on concrete or steel, with abrasion and chemical resistance.||C1 – C3|
|Jotun Barrier 90||Inhibitor coating: Zinc-rich epoxy containing 90% zinc. Suitable for above water and on steel, with abrasion and water resistance.||C1 – C4|
|Hempel Galvosil||Cathodic protection: two-component, solvent-borne, self-curing, inorganic zinc silicate with outstanding resistance against weathering and abrasion.||C3 – C4|
|Hempel Hempadur||Galvanising coating: two-component, epoxy based. It cures to a flexible, well-adhering coating with good abrasion and impact resistance. Contains zinc phosphate||C3 – C4|
|Ultrimax 1||Inhibitor coating: Contains zinc phosphate anti-corrosive properties and a high volume of solids.||C1 – C3|
If you are looking for a professional company to apply the anti corrosion 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.
Looking for more information or a partner in anti corrosion coatings? Do not hesitate to contact us; we are dedicated to connecting the coating demand with the supply; together with our partners we will find you the right anti rust coating solution or contractor.