rust

There are various methods for rust removal; however, these approaches are unsuitable for very old or valuable artifacts as they can be destructive, often removing some of the base metal along with the rust. Dissolving rust with acids like phosphoric acid or vinegar can yield good results, but it may also remove surface features preserved in the rust. As a more effective approach to salvage rusted metal rather than merely removing it, the electrolytic method, or electrolysis, was considered. This technique utilizes the flow of electric current in an alkaline solution or electrolyte to convert some corrosion products into a more stable form while loosening remaining corrosion by transforming it into a loosely bound, easily removable deposit. It is important to note that electrolytic cleaning is not suitable for non-ferrous metals such as copper, bronze, brass, pewter, tin, or aluminum. The corrosion products on these metals are seldom formed through electrolytic action, making the process ineffective. While treatment is generally harmless for copper and tin alloys, aluminum may be adversely affected by the alkaline solution and should be avoided. It is a misconception that rust electrolysis is a quick and easy solution for rust removal. The process of removing the loose converted rust after treatment is time-consuming and can be messy; however, the results can be worth the effort. The concept of using electricity to convert rust back into iron is not new, as electrolysis has been employed for metal restoration by collectors and archaeologists for decades, often yielding impressive results with shiny metal visible after proper treatment. Despite its long history, the specific requirements for effective use are sometimes poorly understood, and the equipment can be quite rudimentary. A simple setup using household items is generally sufficient, provided attention is paid to certain details. Commonly recommended equipment includes a plastic container, washing soda, steel plates, and a battery charger. However, substituting a current-limited power supply for the battery charger can improve results significantly. An example of the potential results from the electrolytic process can be illustrated through the treatment of an old horseshoe, approximately over a hundred years old, which was found in a severely corroded state, having spent much time buried in the ground and covered with a thick layer of flaky rust that obscured any surface features.

The electrolytic rust removal process involves several key components and steps. The setup typically includes a non-conductive container filled with a solution of water and washing soda, which acts as the electrolyte. Steel plates, which serve as electrodes, are placed in the solution. The positive electrode, or anode, is connected to the power supply, while the negative electrode, or cathode, is connected to the rusted object. When the electric current is applied, it causes a chemical reaction that reduces the rust (iron oxide) back to iron while simultaneously releasing oxygen at the anode. This reaction loosens the corrosion, allowing it to be easily removed.

The effectiveness of this method depends on several factors, including the concentration of the electrolyte, the distance between the electrodes, and the current applied. For optimal results, the current should be limited to prevent excessive gas generation, which can lead to poor cleaning performance and increased mess. A controlled power supply can be adjusted to maintain the ideal current level throughout the process.

During the treatment, the rusted object should be monitored closely. The duration of the process can vary depending on the extent of the corrosion, typically ranging from a few hours to several days. After treatment, the object should be carefully removed, and the loose rust deposits can be scrubbed away using a soft brush or cloth. It is essential to rinse the object thoroughly to remove any residual electrolyte solution, as this can lead to further corrosion if left untreated.

Overall, the electrolytic rust removal method is a valuable technique for restoring old metal artifacts without causing damage to their underlying structure, provided it is executed with care and attention to detail.There are various obvious methods of rust removal, but these methods are unsuitable for very old or valuable artifacts as they tend to be destructive in use, meaning that along with the rust some of the base metal is also removed. Dissolving the rust with acids such as phosphoric acid or even vinegar can produce good results, but this process can remove surface features

which may have been preserved in the rust. As I required a way of actually trying to salvage some of the rusted metal rather than just removing or dissolving it, these methods were considered inappropriate. This left the electrolytic method, also known as electrolysis, which involves using the passage of an electric current in an alkaline solution, or electrolyte, to do the job of trying to convert some of the corrosion products into a more stable form, whilst loosening the remaining corrosion by converting it into a loosely bound, easily removed deposit.

Please note that electrolytic cleaning is not suitable for non-ferrous metals such as copper, bronze, brass, pewter, tin or aluminium. The corrosion products found on these metals are rarely formed by electrolytic action and therefore the process cannot be reversed electrolytically.

In the case of copper and tin alloys the treatment would be harmless, although aluminium could be adversely affected by the alkaline solution and so should not be subjected to this treatment. Don`t make the mistake of thinking that rust electrolysis is akin to some magical, or quick and easy way of removing rust.

Removing the loose converted rust once treatment has been completed is time consuming and quite messy, but if you are prepared to put in the effort, I believe the results are worth the trouble. The idea of using electricity to convert rust back into iron is not a new one, and electrolysis has been used for metal restoration by collectors and archaeologists for decades and the results can be very impressive, with shiny metal being visible after proper treatment.

The exact requirements, though, are sometimes poorly understood and the equipment often crude in design, although a simple setup constructed using household items is quite adequate as long as attention is paid to certain details. The equipment commonly suggested consists of simply a plastic container, some washing soda, steel plates and a battery charger, although some refinement to this equipment, in particular substituting an appropriate current limited power supply for the battery charger, will pay dividends in improved results, so more details on this later.

I feel it would be useful at this point to give an example of the kind of results that can be obtained using the electrolytic process and to describe the conditions under which they were achieved. After much searching for a suitable subject, I finally decided on an old horseshoe I`d found some months earlier.

This horseshoe was probably well over a hundred years old and in a particularly badly corroded condition, having spent much of its time buried in the ground where it had developed a thick layer of flaky rust which had obliterated any surface features. To the left is a photograph of the shoe, and it is obviously in a very advanced state of corrosion and much damage had ocurred to the underlying metal.

Note that no surface detail can be distinguished, with no nails or their holes visible. Atte 🔗 External reference