Metallising is a process which involves depositing a thin metallic film on the surface of non-metallic objects.

The most common processes of metalisation include:

• Galvanic metallisation
• Thermal metal spraying
• Fire metallisation
• Diffusion metallisation
• Vacuum metallisation
• Contact metallisation

Corrosionpedia explains Metallising

Metallising is a widespread coating process which is used to improve the resistance of a material against corrosion, wear and fatigue. The metallisation process is applied in many industries, such as:

• Defence
• Oil and Gas
• Solar Product Manufacturing
• Aerospace
• Automotive
• Electrical

Thermal spray processes are often referred to as metallising. Metals like zinc, aluminium, silver, etc. are used to deposit in the form of a metallic film on the base material, such as plastic, glass or metal, to prevent corrosion of the base material.

Metallising consists of three steps:

1. The base material is prepared by abrasive blasting, metal spraying, etc., to ensure adhesion of the sprayed metal.

2. A heat source is used to create molten particles of coating material, then an atomiser sprays this molten material onto the substrate.

3. Upon contact, the particles flatten onto the surface, freeze and mechanically bond, firstly onto the roughened substrate and then onto each other as the coating thickness is increased. Once applied the surface can be worked for a smoother surface painted.

The metal used for deposition may be either in the form of wire or powder. When the coating material is used in powder form, it is known as powder metallising. When it is in wire form, the process is called wire metallising. Coating thickness may vary from .004″ to thicker coats in the range of .012″ – .014″.

What is Metallising?

https://www.metallisation.com/videos/arcspray-process/

Metallising is a general term used to describe the process of applying a metal coating on the surface of an object. These coatings serve numerous functions and can be classified as either Finish coatings (anti-corrosion and decorative coatings) or engineered coatings (wear-resistant)

Metallising is a relatively more complex process than anti-corrosive painting. During this method, the coating metal is liquefied, atomised and propelled onto the substrate. The coating metal comes in the form of a solid wire, which is heated and melted in a chamber. Millions of liquid particles are then ejected from the chamber, where they overlap and solidify on the surface to form a protective coating. Metallised surfaces, therefore, have a significantly longer life expectancy than those painted with traditional protective coatings.

As stated previously, metallising involves the projection of molten metal particles onto another surface. The molten metal particles are created by applying a heat source to a solid metal wire (usually aluminium or zinc), followed by an atomization/projection method. When the ejected molten particles come into contact with the substrate, they cool and form a mechanical bond on the surface. As the process continues, the particles bond with each other as the thickness of the coating increases.

Metallising, like all coating processes, starts with substrate preparation. Cleaning methods, such as abrasive blasting, ensure that imperfections, defects and surface contaminants that may adversely affect the coating are removed. (Preparation techniques are examined in Substrate Surface Preparation for Corrosion Prevention.) Next, the appropriate wire material is melted while clean compressed air sprays the droplets onto the substrate to form the coating.

Metallising protects metallic surfaces from corrosion by offering one or both of the following protection mechanisms:

In most steel structures, corrosion requires two essential ingredients: air and moisture. When the metal particles solidify and bond with the structure’s surface, they form an impervious barrier, which prevents air and moisture from coming into contact with the substrate. For example, zinc, a standard coating material, reacts with the atmosphere to form a thin layer of zinc carbonate, which is highly durable and corrosion-resistant.

Given that the right combination of coating and substrate materials is paired together, metallising can also provide galvanic protection. During this protection method, the underlying steel substrate is protected by allowing the coating metal to corrode preferentially. For example, if the coated object is cut or scratched such that the substrate becomes exposed, then the metal coating will sacrifice itself by corroding first.

Metallising is commonly used to protect objects that are too heavy or too large for Hot-dip galvanising.

Arc spraying involves melting the solid coating material using an electrical arc. The typical arc spray process consists of two electrically charged wires aligned in a V-shape. The wires then converge at a point to create an electrical arc. An air nozzle applies a jet of compressed air that atomises the molten metal and projects it toward the substrate.

Protecting External Steel from Wear and Corrosion

If you’re responsible for maintaining external metalwork, corrosion is likely a concern. Moisture, salt in the air, pollution, and temperature changes all take their toll over time. Left untreated, steelwork begins to rust, weakening both appearance and strength.

Whether it’s balconies on a residential block, railings outside a public building, fences along a coastal property, or other forms of architectural steel, we offer a proven method to help extend the lifespan of these installations – thermal spray coatings.

For contractors, developers and architects, it’s a chance to deliver something that lasts without locking yourself into constant maintenance cycles.

Zinc is widely used in arc spraying for anti-corrosion protection and various other applications. When zinc is thermally sprayed onto a surface, it acts as a sacrificial layer, protecting the underlying material. This coating is particularly effective in environments with a pH of 5 or higher, extending the time before the first maintenance is needed. Zinc coating can also be combined with sealers and paints.

RSJ coated with pure zinc metallisation. Black phosphate coat yet to be applied.

This coating method offers extremely long term protection.

Samples of pure zinc metallisation carried out by MSB

The examples below show one plate cut back with a air sander revealing a satin finish or can be left in its out of the gun form for incredible paint adhesion.
This pure zinc coating can be used for any steel body shells, chassis work. Once applied any type of colour coating can be applied. offering outstanding corrosion protection.

When left unpainted this coating will last over 20 years exposed to all weathers. So if you are looking for ultimate anti corrosion protection then you have found it. From replacement car panels to full steel body shells. See the link above showing a Land Rover Chassis being coated and other vehicle projects we have undertaken in the past.

Metallisation of a Land Rover Chassis

Metallisation in progress on a land rover chassis. Note the fine laydown of pure molten zinc particles forming a barrier on the blast cleaned surface.

This is the next best thing to galvanised dipping without the worry of frame distortion or build up of materials in the box sections or any mounting threads.

Once complete it can be wet painted or powder coated.

Hardwood, blast cleaned, coated in zinc then copper metallisation. Something different. New project one off designer a table lamps…

A somewhat unusual approach but this is what the client requested. Blast clean & zinc metallisation. We asked if he was sure. We prefer the parts to be removed before we start on such work.

Hardwood metallation. Light blast work to raise the grain,then coated in pure copper or aluminium. Hard wearing & outstanding. Can be overcoated with clear lacquer. Other pure metal finishes available. Can be used for flooring, window frames, furniture, artwork infact any type of soft or hardwood. For samples please call.

Cast Alloy frame shown in the first three shots. Now finished in metallised pure copper coat. This can be aged with special antique fluid.

Car Tub and Chassis Metallisation

Metallisation of a Manifold

Blast Clean & Zinc Metallisation

A somewhat unusual approach but this is what the client requested… We asked if he was sure. We prefer the parts to be removed before we start on such work.

Exhaust headers Aluminium coated metallisation coating. For a long and reliable life.

For a long and reliable life. Ready to be coated in gloss black heat paint up to 800d cent. A further ceramic colour coat can be applied.

Exhaust Manifold – before & after metallisation

Oversized Bearing Housings

Here is a little trick for oversized bearing housings, This part is an alloy casting and the bearing were a very poor fit. We put our metallistion gun to work and sprayed a pure alloy metal on the surface to build up the walls. This item is now in the engineering shop being milled out to size