Plating vs. Painting for Finishing Sheet Metal Products

Painting Sheet Metal Enclosures

The sheet metal painting process.

Using aluminum for sheet metal fabrication offers a great deal of of flexibility in terms of creating designs and parts with a variety of shapes or designs. Because of this it is often chosen over other materials. However, aluminum is not the strongest or most durable choice, so many fabrication shops offer finishing options, such as electroplating or painting. Both of these options offer significant benefit in either price or durability. Deciding which option makes the most sense will depend in large part on where your enclosure or sheet metal part will be used.


Basics of Electroplating and Sheet Metal Painting

There are a number of different methods for protecting sheet metal prototypes and production pieces. In this realm, electroplating and painting occupy the opposite ends of each spectrum.

Electroplating creates a very thin layer of another metal such as iridite joined to the component over the aluminum base.

Sheet metal painting is essentially similar to the process for painting any other surface. A primer can be applied after lightly sanding the surface and then paints of a variety of colors can be used as a protective coating for the pieces in question.

However, while the processes are relatively similar and straightforward, they offer very different benefits to the finished product following sheet metal fabrication.


Benefits of Electroplating

Electroplating creates a much stronger coating than painting, both in terms of corrosion resistance and limited degradation due to strikes. Additionally, because the metal expands and contracts at the same rate as the coating, it can be used in environments where temperatures can change drastically over time.

Not only does electroplating coat standard products evenly, but it does so even for unique or oddly shaped designs. It is also easier to ensure a relatively even layer of a secondary metal, which is critical when the component has to fit into a system with tight tolerances.

There are also several different metal options that can be used in electroplating. In parts that must be used in concert with others; chrome works as a lining that minimizes friction and wear and also adds an attractive look. Zinc is often used to protect against water damage and tin plating can help when joining dissimilar materials to sheet metal aluminum components.


When Sheet Metal Painting Makes Sense

While electroplating can offer significant resistance to a variety of environmental concerns, in some projects that may be overkill. Painting means that products can be made at a lower cost and in certain cases, the entire part does not need to be sprayed.

If the full surface area does not need to be protected, paint can offer more flexibility than other options. In addition, in consumer-facing applications, there are more varieties of colors that can be used and project engineers can also take advantage of A&E Manufacturing’s silk screen capabilities to add logos and other designs.


Other Sheet Metal Finishing Options

Another choice for finishing the product is the use of powder coating. This coating offers a variety of finishes, including matte and glossy, without adding much to the cost of components. There are many different schools of thought as to which is better (painting or powder coating), and the answer is probably dependent upon the individual needs requirements of the part being made. Throughout the industry the general assumption is that powder coat is more durable than paint, but in A&E Manufacturing’s experience this is not always true. In many cases paint is a better alternative to powder coat due to it’s ability to be reworked in case of scratches or revision changes. Also, we have found that consistency in both color and texture is better with paint because our experienced craftsmen and our ISO Quality System ensures that these factors stay consistent batch to batch. With powder coating we have to rely on the powder manufacturer to produce consistent batches every time, which has proven to be difficult for them to achieve.

The final option is anodizing or sealing. In these finishes, a chemical reaction is induced in the outside layer of the aluminum to make it stiffer but also more brittle. It improves protection against solvents and other corrosives while being cheaper than electroplating.


Get Help from A&E Manufacturing Company, Inc.

Our staff has more than 40 years of experience working with product designers and engineers build out prototype and larger runs of components and enclosures. We will work with you to decide which finish best meets the needs of your design as well as your budget. We have the ability to form a number of different sheet metal parts and can minimize overall project prices thanks to our ISO 9001:2008 certified manufacturing processes. Call us today or fill out the contact form for a consultation about your fabrication needs.