Marine anodes truly are the unsung heroes of successful boat maintenance. These plain metal ingots are usually hidden from view and are unlikely to attract much attention. However, anodes perform a crucial role: protecting boats against galvanic corrosion.

In this guide to boat anodes, we’ll explore how they work and how boat owners can use them effectively.

Oxidation Poses a Serious Risk to Metal Boat Parts

Many boat parts that are made of metal and sit partially or entirely below the waterline (propellers and rudders, for example) would disintegrate rapidly without the help of marine anodes.

When two different types of metal are connected (by which we mean they’re either in direct contact with each other or linked by an electrical system) and immersed in a liquid capable of conducting electricity, such as saltwater, an electrical current flows between them. The current is powered by electrons – these subatomic particles abandon the more electrochemically ‘active’ metal and travel to the other one.

The atoms left behind become ions, which bond with oxygen in the water, producing pernicious metal oxides. This process, known as galvanic corrosion, weakens, breaks down and ultimately destroys the more active metal.

To make matters worse, as The Welding Institute points out, the more active metal disintegrates faster as a result of being connected to the other metal than it would’ve done on its own.

Marine Anodes Can Extend Your Boat’s Lifespan

Galvanic corrosion is a problem that boat owners can’t afford to ignore. It has the potential to severely undermine a vessel’s structure, leading to leaks, poor performance, instability and a host of other issues.

Imagine discovering that your propeller, for instance, is corroding because the combination of steel blades, an aluminium shaft and saltwater has prompted a damaging electrochemical reaction. Repairing or replacing the propeller could be expensive and challenging.

Thankfully, you can avoid that nightmarish scenario and extend your propeller’s lifespan by installing small-but-mighty propeller anodes.

Many Parts of Your Boat Need Protection

Installing marine anodes is a straightforward, efficient way to prevent galvanic corrosion compromising your vessel’s structural integrity.

There are several key areas you’ll want to protect:

  • Hull
  • Engine
  • Rudder
  • Propeller
  • Shaft
  • Bow thruster

Anodes Are Sacrificed to Preserve More Valuable Metals

Anodes made of zinc have long been fitted to boats exposed to saltwater. In fact, they’re sometimes referred to in the UK boating community as boat zincs.

Zinc is extremely electrochemically active – it gives up its electrons far more readily than the metals used in a boat’s structure. As a result, galvanic corrosion targets zinc boat anodes and leaves the vessel itself undamaged.

That explains why boat anodes are also known as sacrificial anodes – they’re sacrificed in order to preserve more valuable metal parts.

Other benefits of using zinc anodes are that they’re affordable, resistant to impacts and tend to corrode fairly evenly.

Tips for Installing and Monitoring Anodes

The way marine anodes are positioned on boats is important. In order to be effective, they need to sit below the waterline. What’s more, each anode must be mounted on a clean, bare, unpainted area of the metal feature you wish to protect, or alternatively connected to it with a wire.

Never apply paint or antifouling solutions to sacrificial anodes – they won’t work if they’re covered up.

Regularly checking anodes and the metal parts they’re designed to protect is an important part of a boat owner’s maintenance routine. You may find it helpful to make a list of where your vessel’s anodes are located so that you won’t miss any during your inspections.

You can expect high-quality marine anodes to last about twelve months. Aim to replace each anode when about half of it has corroded.

Bolts, nuts and screws are commonly used to attach anodes to boats; however, don’t be tempted to reuse old ones when fitting new anodes. To make the most of your new anodes and ensure they’re securely attached to your boat, you’ll want to use fresh fixings.

High-Quality Marine Anodes for UK Boat Owners

As a leading UK marine supplies shop, we pride ourselves on supplying customers with first-class, reliable zinc boat anodes for saltwater exposure. They’re produced by MG Duff and other top marine brands.

You can order from YouBoatMarine.com with confidence – we’ve received numerous five-star reviews. What’s more, online orders are being processed and dispatched as normal during this unprecedented time.

YouBoat can help you to protect your boat and guard against corrosion.