Any metal that reacts with its environment is likely to corrode over a period of time. This is also the case with underwater metals found on boats and marine vessels. Simply stated, anodes are specially-made metal products that are installed on the underwater portions of a boat or vessel.
These anodes are always more active than a marine vessel’s underwater metals. The commonly used metals for cathodic protection include zinc, aluminum and magnesium. They gradually corrode, thus sacrificing themselves first and shielding your boat’s metals from the effects of corrosion. Zinc anodes are the most widely used anodes in salt water bodies. So much so that boatmen often refer to them simply as ‘boat zincs’. They are usually made from pressure die cast zinc and are available in different shapes depending on where they need to be installed. Essentially, anodes bestow your marine vessel with low-cost insurance.
Whether it is zinc or aluminum anodes, they need to be checked periodically, and replaced when they reach a particular percentage of their original size. This enables boat owners to maintain an undisrupted corrosion protection.
The functioning principle of anodes
When two metals come in contact with each other underwater, small amounts of electricity passes between them. Owing to this passage of electricity, the metal that’s more active will begin to corrode. When you install an anode, you introduce a comparatively active metal. This metal needs to be more active than your boat’s underwater metals. Once underwater, the active metal will begin to corrode and protect expensive underwater fittings from deterioration.
Using the right anode at the right place
There are certain thumb rules that need to be followed when using anodes for optimal cathodic protection. Zinc and aluminum anodes are meant for use in saltwater bodies. If your marine vessel is operating in brackish water, both aluminum and zinc can be used. Brackish water comprises a mixture of fresh water and salt water. However, if the water has relatively low salt content, using an aluminum anode is advised as it is more active than zinc. For fresh water applications, only magnesium anodes can be used. These anodes are economical, yet offer excellent corrosion protection in fresh water bodies. Magnesium anodes are available in several shapes and sizes for specific installations.
Purchasing anodes from the right source
One of the smartest ways to produce anodes would be via an online seller. There are a number of manufacturers that sell their products through authorized distributors. These distributors likely have their own website that sells anodes at discounted rates. While purchasing aluminum or zinc anodes, you might want to check if they adhere to Military Specifications. This is an assurance of their quality and performance. For more details about the appropriate use of anodes, speaking with your chosen anode distributor or manufacturer is highly recommended.
