Why is Metal Finishing Important for the Finished Product?
We all know how important first impressions are, and this goes for metal fabrications as well. It’s important that your product is not only functional but that it is visually appealing and free of sharp edges and any defects or deformities. Metal finishing does just that.
Industries such as the computer industry, electric, aerospace, and sporting goods use metal finishing. Metal finishing can increase the lifespan of metal products. Not only does metal finishing protect metal surfaces from corrosion and abrasion, but it also increases the metal’s hardness and eliminates the risk of tarnishing.
If you’re wondering what your options are when it comes to metal finishing, you’re going to want to keep reading. We are going to talk about the importance of metal finishing and what techniques are available to you.
What Is Metal Finishing
Metal finishing is the last step in the fabrication of metal parts. In this process, a coating gets applied to the metal to protect it and give it a specific appearance. Metal finishing also refers to prepping the fabricated parts for coating or just making it look the best it can look.
Metal finishing takes care of tasks such as dressing welds, cleaning up corners, and removing sharp edges. It also smoothes out any imperfections and creates a surface that is ready to be painted.
Appearance is another aspect of metal finishing. It can be brushed for a fashionable look or could be buffed and polished to give a piece a reflective appearance.
Most finishing techniques are done by hand using orbital and belt sanders as well as angle grinders. A metal finisher must be a highly skilled individual because even the slightest mistake during the finishing process could mean having to scrap the job and start over again.
How the Type of the Metal Affects the Finishing Process
The type of metal used in the production of the part is a primary factor when determining which finishing technique to use. For example, you can polish aluminum to a high shine, but it is too pliable to use a grinder. However, stainless polishes well, and since it is a harder metal, you can grind away welds and any other imperfections. It’s important to remember that most metals oxidize quickly, so a protective coating should be applied as soon as possible.
Different Types of Metal Finishing Techniques
The techniques used in metal finishing can vary from highly complex to merely using a buffer. The technique used during the finishing process depends not only on the metal used but also on the intended use of the piece. Let’s learn more about some of the techniques available during the metal finishing process.
Thermal spraying is also known as plasma spray coating. During this process, molten material is applied at a high velocity and cools quickly to form a hard, solid coating. This method provides protection against high temperatures, erosion, corrosion, and wear. And when it is applied correctly, it can change the electrical properties and the appearance of the piece.
Sandblasting is normally chosen because it removes debris, dirt, and particles that can collect on the surface of the metal during processing. Sandblasting requires no further cleaning, which can save time and money. It is also faster than other methods, which increases efficiency and productivity.
Plastic abrasives, corn cob grit, glass beads, aluminum oxide, and silicon carbide are some of the abrasives used during this process. The type of abrasive used will determine the appearance of the finish, which can range from a textured design to a soft satiny finish.
The brushing process is performed using an abrasive belt or a fine bristle brush and leaves a non-reflective, dull surface. Brushing removes imperfections from the metal and creates a textured grain leaving a smooth finish. The appearance of the brushed finish varies based on the type of tool used to do the brushing.
Metals can also be washed or dipped in chemicals during the fabrication process. Chemicals used in metal finishing have particular properties configured for specific metals. These chemicals are used during chemical etching to create a matte surface on the metal.
Abrasive compounds leave a lustrous finish on metal during buff polishing. The compound gets applied to a buffing wheel, and then the wheel does the finishing. Below you will find different types of buffing used in metal finishing.
- Cut buffing — Used to get a smooth-lined finish. Cut buffing is a laborious process as it requires extra effort, time, and pressure.
- Finish buffing — A quicker, easier process that removes fine lines from the metal, creating a bright, polished surface.
- Buff polishing — Used to smooth surfaces and round out edges.
Metal grinding uses attrition, friction, or compression to smooth out a surface. It is used to finish off rough edges, smooth welds, deburr, and create sharp edges. Specific shapes, sizes, and specific features can be made based on the type of grinding method used. Methods of metal grinding include surface, cylindrical, electrochemical, and centerless. If you plan to use grinding in your metal finishing process, it’s important to choose the proper grinding method based on the metal used and the fabricated product.
During the metal plating process, a metal coating is placed on an object giving it a negative charge when placed in metal salt (with a positive charge). The salt ions are attracted to the negative ions in the material and form a thin metal coating that then adheres to the object. Plating a metal surface has benefits such as making the object more resistant to corrosion, increasing durability, improving surface friction, and giving the object a better appearance. Another advantage of coating the metal is that it protects the surface of the original metal.
Powder coating is a popular process due to its durability, high quality, efficiency of production, and compliance with environmental regulations. During the powder coating process, a polymer resin, leveling agents, flow modifiers, pigments, and other additives are melted and mixed into a fine powder. The powder is then applied to the metal using an electrostatic spray. After applying the powder, the piece cures in an oven. Powder coating can remove deformities and other defects.
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These are just a few of the different methods that may be used during the metal finishing process. When deciding the metal finishing method to use, you should consider the type of metal used, the cost, and the amount of time it will take to complete fabrication. Taking all of these aspects into consideration will ensure that the final product will meet all of your needs.At Engineered Mechanical Solutions, we make sure that our newsletter subscribers get notified when we publish a new article. So if you want to stay updated on the latest about custom fabrication, welding, and producing high-quality parts for your projects, subscribe to our newsletter today!