Metal Finishing: Beyond Just a Shine

Metal finishing isn’t just about polishing a surface to a reflective finish or rejuvenating its appearance. Essentially, metal finishing is a procedure used on the outer surface of metal components, changing them from their initial, coarse condition into something useful, long-lasting, and visually appealing. It is the process of providing metals with a protective barrier, a rejuvenation, or a safeguard against the weather.

Why Is Metal Finishing Important for Metals?

Metals, as strong and sturdy as they seem, are not invincible. They tarnish, corrode, and rust. And when these problems happen, the integrity of the material weakens. Metal finishing helps to prevent these troubles from coming a metal’s way. Finishing is the polishing of a metal’s potential. It is the final touch that turns the ordinary into the extraordinary.

A polished, well-finished metal is more stable to wear and tear. It improves conductivity, reduces friction, and provides a protective layer that helps the metal withstand the harsh environments it may encounter.

Choosing a Metal Finishing Process or Method: Key Things to Consider

The process of choosing a metal finishing method is not easy anymore. There is a maze of options, each with its own strengths and quirks. What’s best for one metal might be disastrous for another. What works wonders in one environment might be totally wrong in another.

Factors that help you decide:

Material Type: Different metals react differently to finishing processes. Aluminum, for instance, has its unique set of challenges, while steel has its own characteristics. Know your metal before opting for the finishing method.

Durability Needs: Is the metal going to be used outdoors, exposed to the sun, rain, and all of the elements of nature? Or will it be set in the indoors? The finish you choose has to match the toughness required.

Desired Appearance: The process depends on whether you are after a bright and shiny surface that has a reflective glow or a more understated matte or textured finish. Your aesthetics will decide your finish!

Cost: Not all finishes are created equal in terms of budget. Some are pricey; some are more affordable. Your budget plays a role in the decision.

A Detailed Guide on The Top Methods of Metal Finishing

Sanding

The process of rubbing a surface with abrasive material, such as sandpaper, is a common method of surface finishing. Coarse grit removes material quickly, while finer grit will give your surface a cleaner polish. Aluminum oxide sandpaper or silicon carbide sandpaper is best used for polishing metal. Use water to cool down the surface and reduce the amount of dust created.

Ultrasonic Polishing

Ultrasonic polishing uses a soft, fine-tipped tool mounted on an ultrasonic spindle. The tool operates at a speed of 21,000 to 25,000 strokes per second. With this technology, the polisher is able to complete precise control on finishing fine details of a metal product. The tips do not actually touch the metal. Instead, it releases a pressure wave that safely creates a fine surface polish.

Tumbling

During the tumbling process, loose abrasive media are placed in a chamber along with the products to be finished. The combination is then rotated and/or vibrated, mixing everything together. The process of rubbing abrasives amongst metal objects removes cleans the product’s surface, removes machining marks and scratches, and eliminates burrs and sharp edges.

Magnetic Polishing

If your product has deep holes or grooves, magnetic polishing is a popular method of metal finishing. This process is slightly similar to tumbling, however, it uses magnetized particles instead of abrasive media. A focused magnetic field forces the particles against the hard-to-reach surface. This process is especially helpful in the production of jewelry.

Sandblasting

Sandblasting blasts abrasive media under high pressure. This metal finishing technique uses either air or water to blast the particles out. This provides a smooth, clean finish. The mixture of particles travels through a nozzle and directs them onto the metal piece. Different media types will result in a wide range of possible surface finishes.

Lapping

Lapping requires a soft iron tool and mild abrasive to slowly work the surface of a metal piece with random, light, non-linear motions. This process is done entirely by hand, making it quite time-consuming, but it is ideal for achieving refined flat metal surfaces.

Filing

A hard steel file is sometimes used during metal finishing. This process is relatively inexpensive but requires the work to be done by hand. Files come in various sizes and shapes of teeth. Depending on how coarse the teeth are, you can remove metal surface material relatively quickly.

Advantages of Metal Finishing

Improved Durability: Metal finishing makes your metal tougher. Whether it’s scratches, corrosion, or just general wear, a good finish will provide that much-needed shield.

Enhanced Appearance: Sometimes looks are very important. You can finish a metal surface with a sleek and shiny appearance if you are aiming for a metallic sparkle.

Corrosion Resistance: A protective finish helps guard the metal against the gradual setting of corrosion and rust.

Friction Reduction: Certain types of finishes can reduce friction between moving parts and make mechanical parts move seamlessly. That’s key if you have moving metal parts.

Disadvantages of Metal Finishing

Cost: Finishing can be expensive in certain cases. When it comes to large-scale projects or metals requiring multiple layers of finish, there could be higher expenses.

Maintenance: Depending on the finish that is applied, you may need to reapply or touch up the metal over time. Surfaces that see a lot of wear will need greater maintenance.

Environmental Impact: Finishing processes like electroplating can have significant environmental consequences. This is because of the chemicals involved in the process.

Applications: Where is Metal Finishing used?

It is used pretty much everywhere. From the shiny frame of a smartphone to the chrome parts of a car, metal finishing plays a role. You’ll find it in:

Automotive: Cars need both durable and attractive finishes for their exterior and interior parts.

Electronics: Conductivity is key in electronics. Metal finishing can help to increase its conductivity.

Construction: Building materials need to be tough, weather-resistant, and, sometimes, visually appealing.

Kramer Industries has been serving our valued customers for over 100 years. In that time, we’ve learned a thing or two about the popular method of metal finishing. If your project could use an expert’s help, or if you are simply looking for the best piece of equipment to use, contact Kramer Industries today.