Metal Polishing: Steps, Types, Applications & Tips

Manufacturing parts is a process that uses multiple fabrication methods, and sometimes, these parts have roughness, scratches, and burrs. In order to finish such metal parts, metal polishing is needed.

If you are looking to learn about the ways you can have metal polished and its appearance enhanced, let's take a look at the guide below.

What is Metal Polishing?

Metal polishing is a finishing method that removes the outer surface layer of the metal and improves its appearance. It gives metal parts a smooth finish like a mirror and makes them durable. Metal polishing makes the metals resistant to corrosion, and a uniform layer is achieved.

Steps to Polish Metal

When it comes to metal polishing, there are different steps involved, and these are given below.

• The first step is cleaning the metal, which is to be polished so that any oil or contaminants from the surface are removed.
• Once the metal part is clean, it is ground roughly so that any scratches, marks, or burrs are removed.
• After grinding, the metal part to be polished is subjected to sanding, and a finer grit is used for the process, which adds finish to the component.
• The sanding adds smoothness to the metal surface and is then buffed using a buffing wheel. Buffing wheels help to achieve a mirror-like look on the metal parts.
• The final stage is polishing, in which the polishes are used to achieve the desired finish. Some metals, like stainless steel metal polishing, may need electrochemical processes.

Benefits of Metal Polishing

The process of metal polishing brings multiple benefits, and some of these are as follows:

• The mirror polishing on the metal components improves the quality of the part, along with the aesthetic look.
• Polished metal surfaces are more durable and offer resistance against corrosion.
• The wear resistance of the polished surfaces is high, and it even reduces the friction.
• Metal polishing improves the component's performance, and the stress is distributed evenly.

Types of Metal Polishing

There are different types of methods for metal polishing, and these are as follows:

Hand Polishing

Hand polishing is a method that consists of using different polishing tools and components. The process creates direct contact between the person polishing and the surface of the metal. The time taken by the process of hand polishing is more, but it is an even more controlled and personalized process.

A suitable compound for polishing is chosen, and the metal surface is applied in a circular motion on the surface of the metal. The pressure is moderate, and if needed, the polish is reapplied. The surface of the metal is then cleaned using a soft cloth, and the residue is removed.

Machine Polishing

The machine polishing method uses tools that are powered, like rotary polishers. The metals that are compatible with such tools consist of copper, titanium, stainless steel, nickel, and bronze.

Metal parts used in industries like aerospace, medicine, and electronics use the machine polishing method. The machine polishing process requires the right polishing pad to be applied based on the required polishing.

Some of the polishing pads are composed of wool, microfiber, foam, etc. The polishing compound is applied to the pad and the machine that polishes the components. Once the polish is done, the surface of the metal is cleaned so that any residue is removed.

Electrolytic Polishing

Electrolyte polishing consists of using electrical and chemical processes to apply the polish to the surface of metal. The process consists of placing the metal component as an anode in an electrolytic solution, and the cathode is also submerged. As the electric current passes, the anodic metal surface smoothens by dissolving, and a reflective polish is attained.

Chemical Polishing

Chemical polishing is a method that brightens and smoothens the surface of the metal using chemicals. It is used for complex shapes that have areas that are hard to reach.

Chemical polishing consists of submerging the metal in a chemical bath that has acids and compounds. The chemicals react with metals and smooth the surface, leaving behind a gloss on the surface.

Common Metals Used in Polishing

The metals commonly polished are as follows:

Aluminium

Aluminum is a lightweight metal that is soft and offers more accessibility. It offers a highly reflective finish, which makes it suitable for automobile applications. Aluminum, however, can be scratched and needs a gentle approach while polishing.

Acier inoxydable

Acier inoxydable is known for its corrosion resistance, and it can be polished very well. It is used in such applications that require durability and aesthetics. Such components consist of medical parts and kitchenware.

Brass and Copper

Brass and copper are also soft in nature and can be polished easily; they can attain a mirror-like polish and are used in furniture and decorative items. However, they do tarnish with time and need regular maintenance.

Titane

Titanium is a lightweight metal that is polished through methods like electropolishing. It changes to a smooth surface, and the material integrity is also maintained. The applications of polished titanium are observed in medical implants and aerospace.

Gold and Silver

Gold and silver are precious metals that are polished so that their natural shine can be enhanced. These metals are soft and can be scratched easily; hence, while polishing, a lot of care is required.

Acier à outils

Acier à outils is used for cutting processes and is also polishable. By polishing tool steel, its friction can be reduced.

Applications of Polished Metal Parts

The applications of the polished metal parts are the following:

Automobile : In the automobile industry, parts like exhaust, wheels, engine parts, trims, and bumpers are subject to metal polishing.

Aérospatiale : In the aerospace sector, parts like fuselage trims, turbine blades, and cockpit parts are metal-polished.

Électronique : Electronics like laptop hinges, cases for smartphones, and medical tools require metal polishing.

Médical : In the medical industry, parts like prosthetics, surgical instruments, and implants are subjected to metal polishing.

Marine Equipment: Marine equipment, like anchor chains, deck fittings, and navigational tools, requires metal polishing to withstand the marine environment.

Tips for Getting the Best Metal Polishing

While metal polishing, when you need to attain the best result, some of the tips that you should follow are as follows:

• The tools you choose for polishing should be appropriate; make sure not to overheat and over-rub the surface of the metal. It is even suggested to use abrasive discs that have polyester films so that a uniform roughness is achieved.
• The polishing components should be applied in a consistent direction. It helps to ensure uniformity of the polish and the applied polish access scratches and marks.
• During the process of metal polishing, make sure to wear safety gear. The process of polishing is dangerous. Also, make sure to remove the grease on the metal parts and clean them using a dry microfiber cloth.

Conclusion

The process of metal polishing helps to enhance the overall look and performance of the metal part, and they are used in versatile applications.

If you are looking for metal polishing services, you can have them at DEK. We offer versatile methods for polishing metal parts, and each part is finished very finely. Our advanced equipment and skilled workforce ensure that you get the desired results.