How to Chrome Plate Aluminum

Chrome is an alloy made from copper and nickel. It makes a shiny coating, and is a popular plating material for auto parts. When you send out aluminum 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.

Things You'll Need

• Polish
• Vapor de-greaser
• Caustic cleaner
• Dioxides
• Etching Solution
• Sulfuric acid
• Copper strike
• Nickel
• Water
• Actuator
• Hex Chromate

Instructions

1. Clean and polish the aluminum part. This will prepare its surface for the following steps.

2. Use a vapor de-greaser to remove grease and other impurities from the aluminum part.

3. Dip the aluminum in a caustic cleaner, like sodium hydroxide to slightly corrode the surface of the aluminum. This will prepare the surface for plating by creating a porous and slightly rough surface structure. Finish this process by submerging the aluminum in a dioxide solution, which is an acid bath.

4. Continue to roughen up the surface of your aluminum by using an etching solution. Rinse in water.

5. Expose your aluminum to a bath of charged sulfuric 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 sulfuric acid bath. While charged, raise the temperature of the solution to about 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.

6. Plate your aluminum 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.

Resources

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