There is a lot of confusion about Rust Protection; the following information will help guide you through the mine field to understanding why we've created RustStop as your best defense.
What is Cathodic Protection?
According to the U.S. Navy, Cathodic Protection is the best form of electronic rust prevention. It is widely used at Naval Shore Activities for protecting buried and waterfront structures and for protecting the interiors of water storage tanks. In some cases, such as underground pipelines, their field experience has shown that cathodic protection is such an effective means of providing the required levels of safety in the operation of the systems that they require cathodic protection by regulation.
Rust is an electrochemical reaction caused by the interaction of negative free electrons and positive ions in the metal. As in any electronic process, the positive side, the anode, gets eaten away while the negative side, the cathode, is protected. Cathodic protection interferes with this interaction interrupting the corrosion process. There are two methods of Cathodic Protection:
The first method, Sacrificial Anode, makes use of an anode, usually made from aluminum or zinc, which has a more positive charge than the metal being protected. This potential (Voltage) difference causes a greater attraction of negative free electrons than the ions in the metal. The result is that the anodes now get sacrificed (corroded) and the corrosion process in the metal is interrupted and hence protected. This method relies on there being an electrolyte (current path), such as water, between the anode and the metal,
without this electrolyte, it is ineffective.
The second method, Impressed Current, makes use of a direct electrical current, which interferes with the corrosion process. In this system, the electrical circuit is completed through an inert anode material that is not consumed in the process. This method is effective
but due to the nature of current choosing the easiest path, it is difficult to
protect large areas of metal and so needs very large amounts of current to be effective.
If RustStop uses Cathodic Protection (CP) then how is it effective in atmospheric conditions?
CP, used in its original form, relied upon an electrolyte to bridge the gap between the anode and metal to enable the required current to flow between the two, to interfere with the rusting process.
The reason why it was not effective in atmospheric conditions, for example vehicles, was because of the lack of an electrolyte. This meant it was only effective when the vehicle was totally wet or covered in a conductive coating, i.e. electrolyte.
An adapted version of CP has been developed enabling protection in atmospheric conditions without a constant electrolyte. This technology, Directed Cathodic Protection (DCP) makes use of a clever combination of both sacrificial anode and impressed current technologies. Instead of relying on the electrolyte (water) to provide a path for electrons to flow towards the anodes, a current is impressed onto the vehicle forcing the electrons to flow though the metal and towards positively charge anodes. The anodes corrode (sacrifice) and the corrosion process is interfered with.
RustStop has enhanced this technology for vehicles in a number of ways; firstly the anodes are adhered to the vehicle using a unique, specially designed open-cell tape. This tape is a partial conductor and so forms a constant electrolyte between anode and vehicle. It also has varying resistance levels depending on the humidity or moisture present. This means that in dry conditions it impresses the required current but senses when there is more moisture present and hence a greater rust threat, and then impresses greater levels of current offering greater protection when needed. The unit also outputs a charge of +45 Volts onto the anodes, this high voltage causes a greater attraction of electrons and hence greater protection.
In addition to DCP, RustStop also uses CP in its original form in raining conditions or when there is a high atmospheric humidity or salt content. Even dirt and grime on the vehicle is conductive and so forms an electrolyte for original CP to become effective.
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