How to Prepare a Substrate for Electroplating

While many manufacturers have the basic understanding that electroplating is used to provide a protective metal coating on a metal substrate, they may be less familiar with the various steps involved. An early step in the process is preparing the metal surface before plating. This typically involves cleaning the part as a means of enhancing the surface to make it more receptive to the metal coating.

Prepare a Substrate for Electroplating

  1. Use Electrocleaning for Metal Substrate Preparation – A process known as “electrocleaning” is often used to prepare metal parts for plating. This technique entails connecting the parts to an electric lead from a rectifier and immersing them in an alkaline or another chemical solution. An electric current is then introduced to help produce the desired electrochemical action to stimulate the cleaning process. Electrocleaning can work equally well with rack plating and barrel plating applications.
  2. Choose the Right Cleaning Solution for the Job – To obtain the best electrocleaning results, it’s important to make the best match between cleaning solution and base metal. Using the wrong solution could lead to oxidation or render the substrate’s surface chemically inert, which can ultimately prevent appropriate adhesion of the metal coating when plating. There are three types of solutions that are normally used for most electrocleaning procedures:
    • Standard alkaline cleaners: Can provide an effective cleaning result on steel and steel alloys, copper, nickel and nickel alloys, lead/tin and even titanium.
    • Inhibited alkaline cleaners: Can prevent unwanted chemical reactions from occurring when electrocleaning metals such as brass, zinc, tin, aluminum and aluminum alloys and bronze.
    • Acid cleaners: Recommended for cleaning magnesium and similar metals.

What Soils Can Be Removed by Electrocleaning?

Electrocleaning can work extremely well for removing a wide range of soils and debris, including:

  • Greases
  • Paint
  • Fingerprints
  • Machining oils
  • Hard-water scale
  • Flash rust
  • Waxes
  • Thin phosphate coatings
  • Lubricants
  • Tarnish

Evaluating Electrocleaning Results

There are many ways you can gauge the effectiveness of an electrocleaning process. These include noting the absence of water breaks when rinsing the surface with water after cleaning. You can also wipe the surface with a clean towel or sponge to detect the presence of any remaining dirt or smut.

Additionally, there are ways to determine the success of the cleaning process during post-production. A properly cleaned part will exhibit a uniform finish, with few signs of insufficient coating adhesion. Of course, there are many other unrelated factors that can inhibit uniform coating deposition and adhesion.

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Contact Sharretts Plating Company to Learn More About Metal Cleaning and Preparation

SPC employs highly effective cleaning techniques as part of the metal preparation process prior to plating. Contact us to learn more about our metal cleaning methods and how we incorporate them into our electroplating process.

Updated 1/22/2019