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ELECTROLYSIS is broadly referred to as an electrical influence causing a reaction between an anode and a cathode. In the world of boats, electrolysis is generally referring to the effect of electrical stray currents on metallic components resulting in aggressive corrosion activity. This type of corrosion can bypass anode and directly cause aggressive corrosion.

Protective coatings such as paints and propeller applications can improve the cathodic protection of a vessel as generally they are excellent insulators. Using an over-active anode can contribute to coating loss in a process called “cathodic disbondment”. Achieving the correct balance between protective coatings and the correct anode can ensure maximum efficiencies from both anode and paint systems. Learn More…

Salinity - the saltier, the more rapid anode consumption is.

Water flow rate - more water flow = more anode consumption.

Acidity - can affect the performance of anodes.

Protective coatings - can be excellent insulators, reducing the load on anode systems.

Infrastructure - contributing effects in the environment can modify CP performance.

Connection to shore power - shore power isolation is essential to remove this effect.

Download our Anode Selection Guide to find the ideal cathodic protection for your vessel type.

Cathodic Disbondment occurs when a large potential difference (voltage) occurs between the cathode (protected metal) and the anode. The high drive potential essentially drives off coatings, resulting in coating failure and high levels of marine growth. Maddox Anodes combat this problem by supplying a lower potential anode that has less potential to affect a coating.

Cathodic Disbondment occurs when a large potential difference (voltage) occurs between the cathode (protected metal) and the anode. The high drive potential essentially drives off coatings, resulting in coating failure and high levels of marine growth. Maddox Anodes combat this problem by supplying a lower potential anode that has less potential to affect a coating.

GALVANIC CORROSION is an electrochemical reaction that causes electrons to flow from one metal to another metal, within the same electrolyte. The more active metal (anode) will deplete and essentially electroplate the more passive metal (cathode) with the anode material to achieve parity. A sacrificial anode is introduced into a combination of metals in order to provide the most active metal to protect all others.

Vessels in a marina are interconnected via the common shore earth, which also carries low voltage DC current between them, the marina and other vessels plugged in. Without isolation, the result is more rapid consumption of anodes and then damage to unprotected submerged metal parts. An Electrolysis Blocker™ blocks the damaging DC current, whilst maintaining effective AC earth capability.

This is a common throw-away question, which needs careful consideration: A balance needs to be achieved between: 1. The correct anode type and 2. Sufficient surface area of anode to protect the submerged metals. It is important to remember that if you over-anode with an overly-active anode, you will increase the rate of damage to coatings and increase anode wear. But if you reduce the surface area of anode to reduce the effects of over-protection, you risk galvanic corrosion as there is not enough surface area of anode to provide efficient protection.

The correct coating will indeed. Quality products like PropSpeed and epoxy coatings are excellent insulators and minimise the exposed metals which require cathodic protection. As protective coatings deteriorate there is an increase in the surface area requiring protection which will increase the requirement for anodes. As coating deteriorate, anode consumption increases. So by achieving the correct balance between correct anode and correct coating, you will achieve coating longevity and maximum anode efficiency.

Shaft anodes are unnecessary on fibreglass and timber boats when there is excellent direct-shaft bonding through the Shaft Grounding Strap. Shaft anodes have a tendency to become loose, causing failure in the cathodic protection system. By simplifying the CP system, you only need to maintain bonding within the hull and hull mounted anodes for peace of mind and maximum efficiency. Tips for Bonding your Vessel.pdf