December 24, 2022

How Surface Finish Affects Anodize

A common question we get asked is how anodize is affected by surface finishing. In this post we’ll discuss briefly the importance of surface finishing.

One factor that can significantly impact the effectiveness of anodizing is the surface finish of the metal. A rough or uneven surface can make it more difficult for the anodizing solution to properly bond with the metal, resulting in a weaker and less durable finish. On the other hand, a smooth and uniform surface allows the anodizing solution to adhere more easily, resulting in a stronger and more durable finish.

There are several different factors that can affect the surface finish of a metal before it is anodized. For example, the manufacturing process used to create the metal, such as casting or forging, can leave behind rough or uneven surfaces. Additionally, mechanical processes such as grinding or machining can also leave behind rough or uneven surfaces if not done properly.

To ensure a smooth and uniform surface finish before anodizing, it is important to properly prepare the metal. This may involve using abrasive materials or processes to smooth out any rough or uneven areas.

There are several different methods that can be used to finish the surface of a machined part, including abrasive finishing, polishing, and buffing. Each method has its own set of advantages and disadvantages, and the best choice will depend on the specific requirements of the part.

Abrasive finishing involves using abrasive materials, such as sandpaper or grinding wheels, to remove material from the surface of the part and create a smooth finish. This method is effective for removing rough edges and imperfections, and it can be used to create a wide range of finishes, from very smooth to rough and textured.

Polishing involves using abrasive materials and lubricants to create a high-gloss finish on the surface of the part. This method is often used to create a mirror-like finish on metal parts, and it can be used to achieve a very smooth surface.

Buffing involves using a buffing wheel and a compound, such as a polishing paste, to create a smooth and lustrous finish on the surface of the part. This method is often used to finish metal parts, and it can be used to create a wide range of finishes, from matte to high-gloss.

In addition to improving the appearance of the part, a smooth surface finish can also improve the performance and durability of the part. A smooth finish can reduce the risk of corrosion and wear, and it can also improve the part’s resistance to dirt and debris. In addition, a smooth finish can make the part easier to clean and maintain.

Overall, the surface finish of a metal plays a critical role in the effectiveness of anodizing. A smooth and uniform surface allows the anodizing solution to bond more easily, resulting in a stronger and more durable finish. By carefully preparing the metal and ensuring a smooth surface finish, it is possible to achieve the best possible results with anodizing. In particular, we have found that the corrosion resistance of the anodize is highly dependent on a lower surface roughness. So if corrosion resistance is an important consideration it would be ideal to hold the surface roughness value to under 24 RA.