To the layman, it might seem as though there’s little to the debate of “electroplating vs. electrocoating.” After all, both of these metal finishing processes provide a second “skin” – a new exterior finish.
When executed correctly, both methods also leave an attractive and durable finish. Those “in the know” are conscious of the differences between the two processes, as they lead to far different results.
Minnesota Industrial Coatings (MIC) provides consistently high-quality industrial coatings, including powder coating and electrocoating (e-coating). MIC professionals carefully guide each project through design to delivery, using our eco-sensitive, quality-driven processes. Contact MIC about your project today!
An Overview Of Electroplating
“Electroplating” aptly describes the process by which it’s performed: an electrical current passes through a solution containing a metal object. The electrolyte splits, depositing some of its atoms on the metal object – leaving it electroplated.
For example, if gold-plating is in order, then the electrolyte must be gold-based.
Before electroplating, parts must be cleaned and follow a chemical bath process to prepare or activate a strong bond and strong adhesion. The electroplating bath involves many variables and components. A power supply provides a direct current flow to the parts and the plating bath’s electrical connections.
This current flow initiates the attraction of ions in the solution to the metallic component’s surface. For every mole of electrons transferred to the part, one mole of metallic ions in the solution will adhere. Also, a chemical reaction occurs at the surface, involving the reduction and oxidation of ions.
Since electroplating involves both an electrical and a chemical reaction at the surface, exposure to the plating chemistry is critical to the finished product’s overall performance. Nesting of components will result in a lack of adhesion or coverage on the finished surface.
Why Is Electroplating Performed?
Electroplating adds properties to metal making it desirable for a wide range of industries, including:
- Aerospace and defense,
- Medical and dental,
- Oil and gas, and
Benefits Of Electroplating
Electroplating enhances or modifies the properties of a metallic part.
Depending on the use of the part, a manufacturer may be looking for:
- better wear and abrasion resistance,
- better corrosion protection,
- more excellent lubricity,
- resistance to friction and abrasion,
- improved EMI/RFI shielding,
- temperature and impact resistance,
- improved electrical conductivity,
- improved solderability,
- reduced porosity,
- added hardness or strength,
- or to build up thickness on small or undersized parts.
All of these are benefits electroplating offers.
In addition to the mechanical or functional properties altered during the electroplating process, the overall aesthetics are also important.
Types Of Plating
Gold plating provides excellent electrical conductivity, making it one of the best choices for electrodes, current-carrying pins, and circuit board components. Gold is ideal for protection against intense heat and corrosion in a wide range of environments.
Silver plating is often used during the manufacturing of electronics (over a copper “flash”) and preferred due to its lower electrical resistance.
Nickel plating is standard because it offers superior chemical and corrosion resistance and excellent wear resistance, increasing product life cycles. Nickel also provides a bright surface finish that can be adjusted according to customer specifications.
Copper plating is beneficial before the final layer of metal is deposited.
Automotive parts, circuit boards, and the defense industry regularly use copper plating. The addition of copper before the final metal deposit can also improve the finished piece’s overall aesthetics.
If a single metal does not provide the properties needed, it is also possible to co-deposit two or more metals for an electroplated alloy deposit.
An Overview Of Electrocoating
Electrocoating, also known as “electrodeposition coating” or “e-coating,” is a painting method that uses electrical current to deposit paint on a surface.
How Is Electrocoating Performed?
Electrocoating is when electrically charged particles are deposited out of a water suspension to coat a conductive part. During the electrocoating process, paint is applied to a piece at a particular film thickness regulated by the voltage used. The deposition of e-coating is self-limiting. It slows down as the coating application electrically insulates the part.
It can produce uniform finishes with excellent coverage and outstanding corrosion resistance. Electrocoat is available in decorative colors.
Benefits of E-Coat
There are numerous benefits to e-coating, including cost, line productivity, and environmental advantages.
Electrocoating offers higher transfer efficiency, precise film-build control, and low workforce requirements. Increased line productivity occurs due to faster line speeds, the ability to densely rack parts, non-uniform line loading, and reduction in human fatigue or human error.
The environmental advantages include:
- no- or low-VOC products,
- heavy metal-free products,
- reduced exposure of workers to hazardous materials
- reduced fire hazards
- minimal waste discharge.
Generally, e-coats are either used as a primer or as a topcoat. Electrocoats lend themselves to topcoat applications because they feature excellent UV resistance.
Electrocoats also perform well on their own in single-coat applications. Why? They are generally superior to popular “liquid primer plus topcoat” paint systems because they deliver overall adhesion and corrosion resistance properties.
The Clash Of The Titans – Electroplating vs. Electrocoating
Electrocoating differs from electroplating as it’s performed by applying a free-flowing powder to a surface, then curing it under heat. Like electroplating, the coating is applied to metal surfaces for protective purposes. But unlike electroplated surfaces, powder-coated surfaces are essentially covered in paint – not metal.
Electrocoating leaves a finish stronger than paint, making it desirable in applications where a hard finish is required.
Electroplating applies metallic particles to the surface of the objects. It can be used on metal, plastic, even glass; the metallic particles can be silver, gold, copper, chrome, nickel, etc.
Electrocoating applies organic resin particles on the surface and converts them to an insulating layer on the objects like paint coating. The items must, of course, be metal.
Electroplating has many color options. The surface of the plating is shiny and smooth with a metallic texture. Electroplating offers corrosion resistance; it can increase the object’s hardness to withstand friction. You will also find heat & humidity resistance and lubricity.
Electrocoating has fewer color options, and the surface is matte. Electrocoating does insulate well, providing good heat & humidity resistance. Compared to electroplating, the coating layer is thinner and evenly deposited, applied on every corner of the object. It offers less resistance than electroplating, and it’s cost-effective and environmentally-friendly.
Working On Complex Shapes Or Large Sizes
Let’s face it; manufactured parts come in all sizes and shapes. Electrocoat excels over other technologies because all surfaces receive a consistent film thickness.
The Waste Factor
E-coating is an extremely efficient process. On average, 95 percent (or more) of the process’s components (resin, pigment, and other additives) will eventually be applied and used on the product. Except in the rare cases of catastrophic tank contamination, the amount of paint solids requiring waste treatment on a regular operating basis is minimal.
Talking To The Electrocoating Experts
Now we understand the benefits of electroplating vs. electrocoating. The deciding factor between the two processes is the finished product’s intended use. The more critical the component is in the hi-tech industry, the more likely metal plating services are in order.
MIC provides consistently high-quality industrial coatings, including powder coating and electrocoating (e-coating). MIC professionals carefully guide each project through design to delivery, using our eco-sensitive, quality-driven processes. Contact MIC about your project today!