Copper Periodic Electrolytic Reversal
Introduction
Copper periodic electrolytic reversal (CPR) is the process of using a negative electrical current to cause the oxidation of copper atoms, thus reducing the amount of copper atoms in the material. This process has been used successfully to restore tarnished or corroded copper surfaces, and to improve copper-containing alloys. This paper will discuss the concept of CPR, the benefits of the process, some of the challenges it may present, and cases in which CPR has been applied for various applications.
How Does CPR Work?
CPR applies a low voltage alternating current (AC) to a copper surface. The current drives electrons across the oxide layer, causing oxidation of the copper atoms below the oxide surface. During this reaction, electrons are also driven into the oxidation layer, which causes the thin oxide layer to decompose, resulting in a layer of metallic copper. This process is reversible, and can be repeated many times if desired.
Benefits of CPR
There are numerous advantages of using CPR on a copper surface. CPR helps to neutralize corrosion and reduce tarnish, restoring a desired surface finish. It is also a cost-effective process, reducing the need for additional protective coatings. Additionally, CPR is non-destructive and can be used to restore several layers of tarnish and corrosion. Moreover, CPR does not require the use of harsh or toxic chemicals, providing a more environmentally friendly approach to surface restoration.
Challenges of CPR
When applied properly, CPR results in a thin layer of metallic copper on the treated surface. This layer is often very thin and requires additional protective coatings for further protection. Additionally, CPR does not always succeed in restoring the original shine to a copper surface, often relying on manual polishing and buffing. Furthermore, CPR can be difficult to perform on rough or irregular surfaces, requiring extra time and effort to properly apply.
Demonstrations of CPR
Throughout the years, CPR has been successfully used in some of the following applications:
● Restoration of antique copper items such as jewelry, coins, and kitchen utensils
● De-tarnishing and restoring luster to copper sculptures and outdoor sculptures
● Re-oxidation of corroded copper alloys used in construction
● Re-oxidizing artistically treated copper that has been altered with acids
● Restoration of tarnished copper and brass pot handles and hinges
Conclusion
Copper periodic electrolytic reversal (CPR) is a reliable process for restoring corroded or tarnished copper surfaces. While the process has some challenges and may not always result in a perfect finish, it has proven to be an effective and cost-efficient method for restoring copper surfaces. CPR does not require the use of toxic chemicals or highly specialized techniques, making it accessible to those with no experience in metal restoration. It has been successfully used in restoration of jewelry, coins, sculptures, and other decorative items, as well as in artistically treated and corroded or tarnished alloys.
