Metal Coating

Metal coating

Metal coating – The industrial guardian

For a metal to perform at its best for the longest possible time, it needs the right metal coating.  Choosing the right coating is a matter of understanding your substrate, its intended usage, its environment, and the kind of finish you hope to achieve. Metal coatings provide a layer between the metal substrate and its environment, and this layer can either protect the metal or provide a finish with an intended use, such a non skid paint.

Types of metal coatings include anodization, galvanization, electroplating, powder coating, enamel coating, and coatings for specific purposes, like anti corrosion, non skid, chemical and abrasion resistance.

Metal coatings are used outdoors and indoors, on planes, trains, automobiles, on heavy equipment and structural steel, on kitchen appliances and wheels. Whatever your substrate, there is a coating that is right for you.


Find a metal coating for all your needs

With so many types of metal coating on the market, one of the greatest advantages is that no matter your need, there is an appropriate coating. Coatings are applied to:

Applying metal coating

Applying metal coating can protect your substrate – or you

…Among others. The range of uses reflects the range of application methods, as metal is a versatile substrate.


The metal coating process

You have your substrate, and you know what you want from your coating. So which coating process do you choose?

Anodizing: for aluminum, titanium, and zinc

Also know as electrolytic oxidation, anodizing is the process of forming a layer of oxide on the surface of a substrate. While anodizing is most common with aluminum, it can also be used on other metals such as titanium and zinc. The metal to be coated is immersed in an acidic electrolyte through which a current is run. Oxygen is deposited on the substrate, bonding with the metal itself and forming an oxide. The thicker this oxide layer the “harder”the coating. Finally the coating is sealed.

Because the oxide layer is integrated with the substrate itself , this coating cannot chip or peel. It also is highly durable, easy to maintain, can be finished in many colors and glosses, and protects the substrate from corrosion.

Electroplating: a versatile coating method

Using the process of electrodeposition, electroplating deposits a layer of coating on a substrate immersed in an electrolyte through which an electric current is passed, like anodization. Unlike anodizing, the layer deposited is not an oxide but another metal.

Chrome plating metal coating for automobiles

Chrome plating is often used with car detailing

The most common electroplating metals are zinc, copper, tin, nickel, as well as precious metals such as gold and silver. Electroplating can also be done with alloys like zinc-nickel.

Electroplating is used to build the thickness of a substrate, provide corrosion resistance, increase wear resistance, improve electrical conductivity (if plated with copper), and give a certain appearance, eg. chrome plating.

Galvanizing: for steel and iron

Galvanizing is a metal coating process in which a layer of zinc is applied to a ferrous metal (most often steel or iron) to prevent corrosion. Most common is hot dip galvanizing, where a piece of steel is dipped into a bath of molten zinc. While in the bath the substrate reacts with the molten zinc and forms a tightly bonded alloy coating, so the coating becomes part of the substrate rather than just a surface layer.

The finish is gray (zinc), shiny, and has a crystalline appearance called spangle. Over time all galvanized parts will weather to a uniform matte gray as the coating develops its protective zinc patina.

Hot dip galvanization forms a coating that is tough, durable, anti corrosion, long-lasting, and sustainable.

Powder coating: decorative and protective

Metal coating comes in many different decorative finishes

Applying powder coating provides many different decorative finishes

Powder coating works by spraying an electrostatically charged powder at a grounded substrate. The powder is attracted to the substrate and accelerates towards it, then adheres to it. The substrate is then put into an oven and the powder is cured, melting into a uniform film. Alternately the substrate is heated first, or it is heated then dipped into an aerated, powder-filled bed. The essential process is still the same.

By applying a powder coat to a substrate you are making it more durable, abrasion resistant, fade resistant, long-lasting, and attractive – with the range of finishes available (including iridescent, glitter, gloss and candy) you can have whatever look you need for your final product.

Porcelain enamel coating

Immediately recognizable from its many cookware applications, porcelain enamel coating is the application of a mixture called a frit to a substrate which is then fired. The frit (usually powdered metal oxides and minerals) can be applied dry or suspended in a liquid, and the firing is done at very high temperatures – 1500 °F.

When fired the coating fuses to the substrate and forms a glass layer which will not peel or crack, is corrosion and abrasion resistant, is low friction, and comes in a wide range of high luster color options.

When you combine two coatings to strengthen your substrate’s protection it is called a Duplex System. For example, using a powder coat over hot dip galvanizing will provide multiple types of protection and the longest-lasting results.


The protective power of metal coating

Which coating you choose will be partly determined by the substrate, but also the outcome you want for it. Whether you need anti corrosion coating, fireproofing, anti skid coating, or chemical resistance there is a coating for your needs.

Applying an anti corrosion metal coating will save you money

Applying an anti corrosion metal coating will save you money

Protect metal from corrosion and rust

Anti corrosion protection ensures your metal substrate will have the longest possible lifespan. It acts as a barrier between the substrate and the environment, protecting it from harmful elements such as oxidation, chemicals, moisture, or salt spray. Anti corrosion coatings are available as metal-rich paints, polymer-based paints such as polyurethane, as well as powder coating, and depending on the substrate’s environment they act in different ways to protect it.

Insulate structural steel against fire

One of the real dangers in a fire is that structural steel begins to lose strength at about 600ºF, and this increases rapidly after 700ºF. This leads to structural collapse. You can protect steel from heat by applying an intumescent paint. An intumescent paint is a coating which reacts to fire by swelling, expanding into a foam-like solid (called char) which is a poor heat conductor.

Non skid paint protects from accidents

Non skid paint protects from accidents

The char slowly erodes, insulating the substrate from the flames for up to 120 minutes. This greatly extends evacuation times and allows firefighters more time to get a fire under control. It also protects the steel from damaging temperature fluctuations.

Non-stick coatings

Falls are the leading cause of hospital visits in the US, and metals become perilously slippery under certain conditions. A non slip coating increases the safety of the surface, as well as being easy to clean and waterproof. They are often a two component system, using an epoxy coating as the base and an additive such as anti slip beads or granular aggregate which provides the non skid qualities.


Metal coating products, suppliers and manufacturers

Many brands and products exist on the US market for coating metal, as well as companies for galvanizing and anodizing parts. Brands include Metal Coating Corp, PPG, Rust-Oleum, Sherwin-Williams, and Sika. See our overview US coating manufacturers for metal coating expertise and services.

Paint Property Paint Type Brand
Chemical resistance Epoxy, polyurethane Nitocote, STEEL-IT, Sherwin-Williams
Abrasion resistance Epoxy, polyurethane Metal Coatings Corp, Crossroads, 3M
Anti corrosion Epoxy, polyurethane, fluoropolymers Rust-Oleum, Hempel
Non skid Epoxy West Marine, KiwiGrip, Interlux, Tuff Coat
Fire resistance Intumescent Fireguard, Hilti, FlameOFF

Need more metal coating guidance? Our experts are here to help.

Use our 100% free quoting service and we can match your project to the best products and suppliers for your needs. Let us connect you with the leaders in the industry.

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