Corrosion is a concern for many boaters. Corrosion damage is frequently unsightly, unsafe and also costly.

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It is feasible to rise to the an obstacle posed by miscellaneous sources that corrosion. As Mercury marine says, “Marine corrosion is a truth of boating life, but you can defend your investment v diligence & ideal maintenance.”


Certain kinds of corrosion have the right to devalue your investment in a matter of months or even days. Plenty of boating enthusiasts execute not understand what particular threats come look out for. Let’s shine some light ~ above the topic.

Types that Corrosion

An post in Seaworthy discusses varieties of corrosion that boaters combat, consisting of simple, electrolytic, crevice and also galvanic.


Simple corrosion occurs when molecules on a metal surface bond v oxygen. The procedure is called oxidation. Moisture accelerates the chemistry reaction. In maritime applications, aluminum deteriorates right into aluminum oxide, a grayish substance.

Fortunately, stainless steel and other coatings avoid oxidation. Basic corrosion in a marine setting is often really gradual. Because that example, straightforward corrosion the a copper propeller occurs at a slow-moving rate. Therefore slow, in fact, the the process may not impact service life.


In marine settings, stray electrical present quickly increases corrosion. Electrical shorts are frequently the culprit. Countless of them happen in the 12-volt battery systems typical on boats. When there’s a short, electrical current may circulation through one underwater steel fitting. The result electrolytic corrosion can do serious damages in days or hours. Regular boat inspections and also prompt diagnosis attend to the threat posed by electrolytic corrosion.


Crevice corrosion is a danger to stainless steel offered in marine environments. The “stainless” nature that the steel is due to its oxidized surface. Here, oxidation is actually beneficial, inhibiting corrosion. When moisture combines through a shortage the oxygen, difficulties arise. Undesirable leaks may result in crevice corrosion in bolts and fittings.


Galvanic corrosion is a far-ranging concern in maritime environments. Different metals immersed in water essentially end up being a battery. A steel with an ext negatively charged ions acts together the anode. Ions circulation to the much less negatively charged steel – the cathode. The higher the distinction in voltage between the two, the an ext rapid the ns of anode material. Galvanic corrosion is the result.

In a naval environment, serious galvanic corrosion can happen in months. Fortunately, the proper use the sacrificial anodes controls the process.

Sacrificial anodes – A sacrificial anode includes a metal reduced on the galvanic table 보다 the other steels on the boat. That takes the corrosive threat away from metal hulls and also stern drives.

In countless systems, various metals room bonded together right into a single cathode using 8 AWG environment-friendly insulated cable (ABYC conventional E-2). It’s important to check the boat’s sacrificial anodes top top a consistent basis.

Three metals are popular in sacrificial anodes. Aluminum anodes are frequently used in watercrafts used in both freshwater and saltwater. Magnesium anodes are ideal for freshwater applications. In the past, zinc anodes were common. However, freshwater reasons a coating that zinc oxide that limits effectiveness.

Supplementary systems – Sacrificial anodes are not constantly enough. Sometimes, the area that demands protection is also large. Or, the voltage difference between the anode and the cathode is insufficient.

As a result, the is often crucial to include a supplemental system. A sensor it is provided real-time data, signaling the system to increase the electrical current to protect linked metals. Mercury Marine’s MerCathode device is an example of a supplemental system.

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Periodic Inspections and Maintenance

Professional inspections and prompt maintenance help you guard against corrosive damage. Come protect against electrolytic corrosion, make certain your boat’s electric system is in good working order. Minimize the potential for electrical shorts with a well-maintained battery system. Counter the threat of galvanic corrosion with sacrificial anodes and supplementary systems. Certain they work-related according to spec.