Chrome is an alloy made from copper and nickel. It makes a shiny coating, and is a popular plating material for car parts. When you send out aluminium parts to be chrome plated it is very expensive because chrome plating involves caustic and highly toxic chemicals, making the costs worth the investment. Therefore, while it is usually a better option to send out a single piece to be chrome plated, if you are interested in starting your own chrome plating business or if you are working on a large project, you can set up your own chrome plating stations at home.
- Skill level:
Things you need
- Vapor degreaser
- Caustic cleaner
- Etching Solution
- Sulfuric acid
- Copper strike
- Hex Chromate
Clean and polish the aluminium part. This will prepare its surface for the following steps.
Use a vapour degreaser to remove grease and other impurities from the aluminium part.
Dip the aluminium in a caustic cleaner, like sodium hydroxide to slightly corrode the surface of the aluminium. This will prepare the surface for plating by creating a porous and slightly rough surface structure. Finish this process by submerging the aluminium in a dioxide solution, which is an acid bath.
Continue to roughen up the surface of your aluminium by using an etching solution. Rinse in water.
Expose your aluminium to a bath of charged sulphuric acid. This process is sometimes referred to as electrolysis. You can charge your acid bath by placing charging plates attached to a 12V charger into the sulphuric acid bath. While charged, raise the temperature of the solution to about 46.1 degrees C (115 degrees F) and continue to run an AC current through the solution for about 10 minutes. When the process is over, rinse the part in water.
Plate your aluminium part by dipping your part first in a copper strike bath made up of liquid copper, then in a nickel strike solution which contains liquid nickel. Rinse the part in water. Then use an actuator, or mechanical device, to move your part to the hex chromate solution to complete the process. Remove the part from the final solution and you will have a chrome plated part. The entire process takes several hours.