Surface treatments are essential in modern manufacturing, helping to protect and enhance the surfaces of everything from kitchen appliances to aircraft components. By modifying, refining or coating the outer layer of a material, surface treatments add value in ways that go beyond appearance – improving durability, functionality, and performance.

How surface treatments work

Broadly speaking, surface treatments fall into three categories: removal, modification, and coating. Removal processes such as grinding or polishing help prepare the material by smoothing it or eliminating impurities. These are often used as pretreatments before painting or bonding.

Modification methods, including heat treatment or chemical conversion, change the surface itself to improve properties like hardness or corrosion resistance. Shot peening, for instance, bombards the surface with small particles to increase fatigue resistance-an approach especially common in high-performance applications.

Coating techniques, meanwhile, apply a new layer to the base material. This might be for protection, decoration, or to add special properties. Examples include painting, anodising, and thermal spraying. Coatings often need to adhere securely, so some surfaces may first be roughened by processes such as shot blasting.

The BBC’s bitesize series highlights how surface treatment is a key part of product design and engineering, playing a role not just in how something looks, but in how it performs and lasts.

Common coating techniques

Among the most familiar surface treatments is painting, which offers both protective and decorative benefits. It can be applied using brushes, rollers or more advanced methods such as electrodeposition coating.

For a tougher, more durable finish, plating is often used. This involves depositing a metal film, such as zinc or tin, onto a surface to improve wear and corrosion resistance. Companies such as poeton.co.uk/surface-treatments offer specialised options for industries requiring high-performance finishes.

Anodising is another technique, typically used on aluminium, where the surface is oxidised to increase hardness and electrical insulation. Thermal spraying, meanwhile, allows for a wide range of materials to be melted and sprayed onto a component to form a protective layer.

These techniques ensure that products not only look good, but also perform reliably in demanding environments.