Skip to content

EvriGard Australia

Electronic Rust Protection Technologies

There are a number of electronic rust protection technologies used, some more effective than others and some only suited to certain applications but ineffective for use on motor vehicles. Below is an overview of the various forms of ERP and the benefits and limitations associated with them:


Sacrificial Anode Technology (Cathodic Protection) Stand-alone or Electronic:

Anode Systems

This can be found in two forms, stand-alone or electronic. In the case of stand-alone Cathodic Protection, there is no external power source but rather relies on the natural potential difference (charge) between two metals to provide protection. For example on ships made of steel, they weld on anodes made of zinc, or zinc, aluminium and magnesium alloy. When the anodes are submerged in water, the natural potential difference between the steel and the anode causes a transfer of electrons and the metal with the higher charge (the anode), is sacrificed and the steel (cathode) is protected. In the case of Electronic Cathodic Protection, rather than relying on the natural potential difference, an electronic power source forces the anodes to be at a higher potential, so the anode material is not as crucial. This is often used to protect underground pipelines where the anodes are buried in the soil near to the pipelines and charged using a high powered electrical source and protection is achieved through the transfer of electrons between anode and pipe through the moist soil. Both variations of this form of protection relies on the structure and anodes being surrounded by a continuous electrolyte in contact with the entire structure, e.g. water in the case of a ship and moist soil in the case of underground pipelines. When there is no electrolyte, like the ship being out of the water, or the soil being too dry to conduct, there is virtually zero protection.


This form of rust protection for vehicles is not-suitable and not very effective because the vehicle is not submerged and the anodes, in effect, are isolated from the body of the vehicle by using some form of adhesive tape and there is no conductivity until the anode is submerged. These types of systems for vehicles often suggest that the anodes be mounted in areas that get wet when it rains to try and achieve the electrolyte, but even in this case, the protection is very localised and only areas of metal that are in contact with the same water that is in contact with anode is protected. This is why these systems often rely on having numerous anodes around the vehicle to try and achieve more coverage, but once the anodes are not submerged, very little protection is achieved.
The anodes are also designed to corrode and the white oxidation that can build up can cause damage to the paint if not cleaned immediately, quite a job when you have numerous anodes around the vehicle.



You only have to do a search on cathodic protection for vehicles on the internet to see why it is not suited to vehicle protection.




Impressed Current Technology:


This involves purely outputing a direct high powered current through a metal structure, as used in some of the naval vessels. In this technology, the aim is to impress enough current that the flow of free electrons is strong enough so as to prevent them from being free enough to react an form rust. The problem with this technology is that it required high powered current flow, in excess of 15 Amps is used on the naval vessels, and if you try and draw more than about 0.5 Amps from a car battery, it would be flat overnight. When only small amounts of current is impressed, like the basic ERP unit available, the flow of electrons, and hence protection is very localised due to the fact that the flow of electrons settle into a thin flow stream between connection points.




Capacitive Coupling Technology:


This technology has the output wires from the control module connected to pads which are held at a positive charge, the structure being protected is then relatively negative and it then relies on the paintwork between the pad and the metal to become a dielectric (insulative layer). In effect creating a capacitor. This then holds the free electrons in the metal static and inhibits the loss of these electrons, reducing rust. This technology is quite effective until there is breaks in the dielectric (layer of paint), which means that any chips and scratches need to be touched up for it to maintain effectiveness, which is not always practical in vehicle applications. The other problem is that it is not effective on existing rust due to the fact that there is no dielectric and it is very difficutl to hold a charge on irregular, sharp and bare metal, like rust.




Capacitively Pulsed Technology:


This is the most effective form of rust protection and what EvriGard has improved on to be one of the most effective systems available worldwide. It involves the rapid capacitive build-up of charge and then release through the body of the vehicle at a multi-frequency pulse which effectively saturates the entire body of the vehicle with excess free electrons, countering electron-loss and rust formation. We do not claim to have the miracle cure for rust, and if anyone does, BEWARE, we are just providing the most effective way of controlling the rusting process and slowing down the spread of existing rust at the same time. See How EG Works for more details.  






Login Form