If you work in an industry that uses large machinery, then you’ll be aware of the importance of keeping those machines in as good a condition as possible. Many different industries rely on hydraulic machinery, including the industrial, marine and military sectors, and employees will know that a broken or underperforming machinery part can slow down production, and cost you and your business a lot in both time and money.
One way to protect these parts is by investing in a quality finish for your machinery, and there are many benefits to be found from using one of these product finishing methods. If you’d like to know more about the different methods of metal finishing, and how it can benefit your business and machines, then read on to find out more.
What is metal finishing?
Metal finishing is a blanket term for several different processes, which involve applying a metal coating to the surface of a metallic part. It can also refer to the processes of cleaning, polishing or generally improving the surface of any metal machine or part. Metal can become damaged over time due to regular wear and tear, chemicals or air pollutants, but applying a metal finish can help the parts last longer and stay in good condition.
There are several different methods of metal finishing which we will discuss in more detail further on, but all processes begin with degreasing; this removes any grease left behind from the metal’s manufacture. Next, the metal will be cleaned to remove any dirt or impurities from the surface, and to ensure it’s ready to receive your chosen method of metal finishing.
The benefits of investing in metal finishing
Choosing metal finishing for your industrial machinery has many benefits, from reducing the effects of corrosion and rusting, to serving as a primer coating which will make paint adhesion easier. Applying a finish also strengthens the part/machine in question, and makes it much more resistant to everyday wear and tear, which can be invaluable if the machinery gets a lot of use.
Other valuable benefits include, reducing the friction between moving parts, improving aesthetic appearances, enhancing chemical resistance, and it can even make a surface electrically conductive.
Types of finishing methods
There are many different types of industrial finishing methods that can be used to finish metal, including electroplating, cladding, powder coating and more. We will examine some of the most popular methods of metal finishing in more detail below.
Also known as electrodeposition, this method involves depositing a metal or metal alloy onto the surface of the base material. It’s achieved by passing an electric current through a liquid which contains dissolved ions of both the metal and the base material. The object being finished acts as a cathode; attracting the metal ions found in the plating liquid.
Popular electroplating methods include rack plating (where the parts being plated are affixed to a jig), or barrel plating (where smaller parts are tumbled together in a barrel-shaped cage). Electroplating can also be used to coat plastic and other non-metallic materials, but this process is much more complicated and requires a high level of expertise.
This is similar to the above method, in that the parts are also placed in a liquid solution containing ions of the desired metal finish (usually nickel or copper). In this case, the coating is applied using a chemical reaction instead of electricity, and the plating bath will contain a complexing agent to ensure all components remain stable during the process.
Cladding uses a mechanical process to bond the metal coating to the machine or part surface, using heat and pressure. This method is able to provide a thicker metal coating than if you were to use electroplating or electroless plating, and it requires less preparation of the surfaces. It uses a lot of specialist equipment however, so can be more costly than some alternative methods.
This is often used to provide an additional layer of corrosion protection, but it can be used as a plating process in its own right. Passivation involves applying a metal oxide coating, which can help to slow the rusting process, and ensure your parts last longer. Passivation coatings also come in a variety of colours, which can improve the appearance of any surface you apply it to.
This is another method similar to electroplating, but the liquid solution contains electrically charged paint particles instead of ions. E-coating can be used on almost any type of metal, and is often chosen as a type of primer coating applied to a surface before being painted, as adding a coating helps paint adhesion.
As the name suggests, this type of metal finish uses a powder substance rather than a liquid. Powder coatings offer more thickness than their liquid alternatives, and they’re made up of a mix of pigments, levelling agents and other additives. The powder is electrostatically deposited onto the surface before the parts are cured in a specially designed oven. This produces a chemical reaction to strongly bond the powder coating to the parts surface.
This electrochemical metal finishing process is essentially the opposite of electroplating; instead of depositing metal ions onto a surface, this removes them to give a smooth streamlined texture. The object being polished is placed in an electrolyte bath (turning it into an anode), and is then connected to a DC power supply (which acts as the cathode). Electropolishing is highly effective if you want to remove debris from a surface, smooth things down, or even slightly reduce the size of a part.
This produces a similar effect to that of electropolishing, but the method is much simpler. Instead of using electrical or chemical processes, buff polishing simply uses a cloth wheel to buff the surface of the metal to a glossy decorative sheen.
Also known as mechanical surface finishing, this is chosen as an affordable way to polish several parts at once. This can rapidly increase productivity and decrease production times, and mass finishing actually comprises several metal finishing techniques, including tumble finishing and vibratory finishing.
Wet spray coatings are particularly well suited to parts containing heat vulnerable components or if parts are made from mixed materials. These wet paint coatings are suitable for most metals, and offer many benefits including increased durability and a range of colours to improve the aesthetics of your metal fabrications.
Shot blasting is a useful all in one technique which can be used to clean, polish and strengthen metal. It’s used by a wide variety of industries who use metal parts or machines, including construction, ship building, rail and aerospace. Also known as abrasive blasting or sandblasting, this method works by firing a high pressure stream of abrasive material at a surface. It eliminates the need to use chemicals, while still revealing a smooth, clean surface and removing any dirt such as rust or grime.
If you’re in need of professional product finishing services for your metal parts, get in touch with H P Hydraulics. We offer wet spraying and shot blasting services, plus a team of hydraulic engineers to carry out any repairs, hydraulic parts or other hydraulic services. We have years of experience working in the hydraulic sector, so for reliable, professional services, you can rely on us. We also offer commercial vehicle repair, and are one of the leading hydraulic fitting suppliers, so for more information, visit our website today or give us a call on 01329 828 877.