as seen in

Hard Hat News

Serving Contractors for Excavating, Construction, Demolition, Underground Utility Construction, Land Clearing/Landscaping, Paving and Bridge Construction.

Electronic Rust Protection

Nuts 'n' Bolts by Bill Siuru

William D. Siuru Jr., PhD, PE, is a retired USAF Colonel currently working as an automotive journalist writing about automobiles, computers, construction, and power generation. He taught in the civil and mechanical engineering department at West Point and commanded the research laboratory at the Air Force Academy. His PhD is in Mechanical Engineering.

Rust can take an expensive toll on equipment. Sprayed-on rust-proofing coatings inhibit rust, but can fail if bare metal is exposed to give corrosion a place to start. Also it is impossible to coat every seam, spot-welded joint, bolt and screw.

CounterAct CPR (Corrosion Protection Resources) has developed a corrosion protection process called "capacitive coupling" for protection not provided by coatings. Basically, CounterAct's Electrostatic Corrosion Protection System delivers a small, negative electrostatic surface charge to all the commonly grounded metal surfaces including crevices and hidden areas.

While CounterAct is not 100% effective in stopping rust it can significantly slow the process. Independent laboratory testing has shown CounterAct's process can reduce rust and corrosion by over 80%. It is not only for new equipment, usually the case for coatings, it can be used on old items even when corrosion has started.
I was initially skeptical. Was this a serious product that works or gadget to fetch a quick buck? What caught my attention was that the technique has a 15-year history of successful applications with some very serious corrosion problems like brine harvesting trucks on Utah's Great Salt Lake, snowplowing and salting of roads in Iowa, and protecting surf equipment on beaches in Australia. The company expects to have FAA approval for use on airliners in the near future.

CounterAct's electronic rust prevention technology is based on the principle that corrosion is an electrochemical reaction and thus it can be controlled electronically. Iron and oxygen have chemically opposite charges and therefore seek to combine to form rust since opposites attract. The faster that iron combines with oxygen, the faster the deterioration. Metal bodies tend to have a positive electrical charge in an area where rust is occurring.

CounterAct's capacitive coupling process induces a negative surface charge on the metal body and polarizes the microscopic layers of electrical charges that occur along a corroding metal surface. This makes it very difficult for the opposite charges of iron and oxygen to connect as they have to battle with these polarized layers of charges. This negative surface charge and its corresponding polarized charge layers reduces the rate at which the iron and oxygen combine resulting in a reduction in the rate corrosion occurs.

CounterAct's system consists of three primary components: (1) Power Supply and Control Module, (2) Removable Modular Wiring Harness and (3) Programmed Capacitive Couplers.

The small pulsed, 12 or 24-volt DC power supply delivers the right amount of current to the capacitive couplers to generate an electrostatic field of proper strength to reduce ion mobility, the basis of the corrosion process. The removable modular wiring harness allows easy access to the power supply/control module for inspection or easy transfer of the system to another vehicle.

The programmed capacitive couplers are attached to the protected metal surface with aircraft grade, peel-and-stick adhesive. The coupler is a small flexible square with a thin copper plate separated from the body by an insulator and separated from the moisture layer on the body by an epoxy coating. When charged by the power supply/control module, the coupler functions like the positive half of a capacitor inducing a specific limited range of negative electrostatic surface charge via capacitive coupling. The metal body serves as the negative half of a capacitor. More than one coupler is required on larger trucks and equipment.

While a high voltage of about 400 V is used, the current drawn is less than 50 milliamps, less than a typical digital clock, and so there is no chance of electrical shock.

It does not interfere with computers, radios and other electronic equipment. The power supply and control module features solid-state circuitry embedded in electronics grade epoxy encapsulant for long life and durability in any climate.

While CounterAct's electrostatic corrosion control technology can, in a general sense, is associated with the family of traditional electronic rustproofing or corrosion proofing methods, the technology should not be confused with conventional "impressed current cathodic protection" or "anodic protection " commonly used for corrosion control on underground tanks, pipelines and other buried and submerged structures . While used for over half a century, these techniques works well in their environments but cannot prevent corrosion in open air because of lack of sufficiently conductive medium to carry the protective current to the structure to be protected. CounterAct technology actually begins where traditional electronic rustproofing methods leave off. The CounterAct electrostatic corrosion protection sets itself apart from these more traditional forms of electronic rustproofing because it was designed from the outset to solve open-air corrosion problems.