As the final step in the fabrication process, custom metal finishing prepares metal products or components for their designed purpose. This process provides many advantages, such as ensuring better resistance to corrosion or chemicals. Custom metal finishing also improves the specific properties of metal workpieces, making them more durable. Choosing the right finish for a metal fabrication project largely depends on its end use.
What is Custom Metal Finishing?
After machining metal components, they must be assembled into a final product. These parts often go through a finishing process to improve performance. Custom metal finishing can be done by many methods, though all these processes involve treating metal surfaces. This may entail building a layer to protect metal surfaces, though certain types of cleaning, polishing, or other exterior enhancements are also considered types of finishing.
There are numerous methods for finishing metal that not only extend the lifespan of a metal product but also add to its aesthetics. To choose the best custom metal finishing for a project, it’s important to examine these methods and their advantages. The metal finishing industry has a wide range of processes, each method with its benefits.
Types of Custom Metal Finishing Processes & Their Advantages
Each custom metal finishing process has advantages, often dependent upon the application. Often these finishes are utilized in conjunction with one another to create more durable and versatile coatings.
Passivation
Passivation is used for appending metal with a protective layer for corrosion resistance. It’s important to note the difference between mechanical cleaning of parts and coating finishes, such as anodizing. RP Abrasives’ chemical passivation process uses deionized water and acids to make stainless steel more resistant to corrosion or rusting, which is especially important for the medical and food service industries. It also created an even, smooth, and aesthetically pleasing finish. Our citric acid passivation process uses a citric acid solution for a more environmentally friendly yet consistent, evenly-passivated finish.
The advantages of passivation include:
- Improve corrosion resistance
- Remove surface contamination
- Reduce the risk of future part contamination
- Extend part life and functionality
Deburring
The deburring process removes unwanted materials from the surface of fabricated parts, referred to as “burrs.” Nearly every industry requires parts to meet certain safety, and functionality specifications, so deburring is a prevalent metal finishing process. Deburring can be done by hand, bead blasting, tumbling, or even a combination of several methods – RP Abrasives can assess and determine the best method depending on the part’s requirements. Hand deburring uses small handheld tools to access hard-to-reach receives, creating a precise finish that machines alone cannot offer. Batch deburring, also called “mass finishing,” uses various tumblers, such as vibratory, centrifugal, and high-energy, to reach the desired finish of several parts at once.
The advantages of deburring include:
- Reach the desired finish without compromising the part
- Effective for even the smallest parts and components
- Smooth, even finish
Plating
This manufacturing process involves applying a thin metal layer onto the surface’s substrate. Common plating materials include aluminum, chromium, copper and nickel, which are then deposited and fused onto the surface, bonding them through heat and pressure.
The advantages of plating include:
- Hardening surfaces to enhance strength
- Improving how well paint adheres to the surface.
- Inhibiting galvanic and other corrosion.
- Making surfaces more aesthetically pleasing.
- Reducing surface friction.
A tougher metal that better resists abrasion or other wear will be added to provide a more stable surface.
Anodizing
Used as a particularly effective custom finishing process for aluminum, anodizing converts the metal into aluminum oxide through an acidic solution, increasing its corrosion resistance. Anodizing can also be used to apply a wafer-thin film of aluminum to shield other nonferrous metal surfaces. The technique alters the surface’s molecular structure, enhancing its protective properties.
Advantages of anodizing include:
- Creating a stronger and harder finish.
- Protecting from UV radiation.
- Reducing effects of wear.
- Resisting corrosion.
Anodized finishes aren’t typically colored, though dyes can be easily added to make surfaces more appealing.
Abrasive Blasting (AKA Bead Blasting or Sand Blasting)
Unlike other custom metal finishing methods, abrasive blasting involves wearing away imperfections via abrasion and friction rather than adding a coat. With this method, silica sand, silica oxide, or other abrasive material is sprayed at a high velocity over the surface to smooth it out. Different abrasive blasting techniques can be used depending on the finished metal. Soda is used for more delicate pieces, as it won’t react chemically with or otherwise damage the surface. Steel grit is often used to prepare the surface for painting or to clean rust from hard metal surfaces. Another method used to prepare a surface for painting uses glass beads, which are used for softer metals like aluminum.
Benefits of abrasive blasting include:
- Combining surface finishing with cleaning in a single process.
- Eliminating small surface imperfections.
- Removing contaminants to create a clean, smooth finish.
While abrasive blasting is used to prepare metal surfaces for painting, it’s also used before plating or other custom metal finishing methods. It’s also sometimes used to change the shape or enlarge the surface area of a workpiece.
Polishing
A simple process, polishing as a method of custom metal finishing offers a means to give the metal a brighter shine through gentle friction. Though mainly used for aesthetics, it can also be used to prepare before other processes, including powder coating or plating.
Benefits of polishing include:
- Giving surfaces a more pleasing appearance.
- Preparing surfaces for other finishing techniques.
- Removing minor flaws.
Polishing works on many different metals, including brass, chromium, stainless steel, and others, along with plated or finished items.
Custom Metal Finishing Services by RP Abrasives
RP Abrasives offers a variety of custom metal finishing solutions to meet the needs of our customers. Additionally, our capabilities allow us to combine multiple finishing techniques to ensure the surfaces of metal components and other products last longer and perform exactly as they should.
Our company’s specialized metal finishing services include blasting, buffing, deburring, passivation, polishing, and tumbling, or combinations thereof. For more detailed information on our services and how RP Abrasives can serve your needs, we invite you to contact us today or, for those who already know what they need, to request a quote.