Ship in port

Preventing Ship Corrosion With Zinc Cathodic Anodes

Working with metal in any industry comes with varying levels of concern over corrosion. For maritime industries, corrosion can quickly lead to damaged parts, costly repairs, and a delay in processes.

Each part of a ship with exposure to the water will begin corroding due to the high salinity of sea and ocean water. Countering this process involves breaking the flow of electricity seawater facilitates, primarily through the use of marine anodes like zinc cathodic anode coatings.

Understanding Zinc Cathodic Anodes

Corrosion is a simple reaction, yet finding long-term solutions has been a challenge due to the number of sources of corrosion that exist. When any metal is exposed to chemical or electrochemical reactions, it begins oxidizing, a compositional change that results in a loss of energy and strength.

As a ship corrodes, it loses strength and structural integrity, which can lead to unsafe operation as the corrosion eats away at the outer layer of metal. You can see this happen over time as corrosion causes chunks and flakes of the metal to fall off. Salt water is an electrolyte that acts as the catalyst for these reactions.

The most popular metal for shipbuilding remains mild steel due to its affordability, workability, and strength. Unfortunately, this type of steel corrodes quickly in salt water, losing its inherent strength if not properly protected.

This is where zinc-rich outer platings have come into the picture in the form of cathodic protection. The high levels of zinc create a sacrificial barrier between the base metal and surrounding salt water. Zinc cathodic anodes corrode more easily than those of metals such as steel, protecting the ship so long as a layer of coating remains.

Choosing the Right Zinc Cathodic Anodes

While high levels of zinc in a ship’s coating will always provide some protection, getting the most out of applying a new coating requires the proper composition. A new ship that receives an initial zinc coating followed by regular upkeep will have a longer service life than similar vessels.

This improved service life also comes with fewer repair costs and time loss. Zinc cathodic anodes that have proven effective in achieving high levels of protection fall into four categories: ZHC, ZHS, ZSS, and ZEP. These anodes are often referred to as military anodes as they meet federal requirements to be used in military and government applications.

Both ZHS and ZHC anodes are used commonly for hull plating since they can easily be bolted or welded to the exterior of a ship. Each possess two straps of galvanized steel for mounting and are ideal for large-scale plating projects. Salt water storage tanks utilize these anodes for internal protection, as well.

ZSS and ZEP anodes offer the same protection as ZHS and ZHC, but opt for a form factor that makes intricate hull and tank designs easier to plate. ZSS is a slimmer bar of zinc with one galvanized steel strap, while ZEP comes in 1-inch-thick discs.

Staying Ship-Shape at Sea

Preventing corrosion on saltwater is a key pillar in successful vessel operations. Zinc cathodic anodes are an effective method to achieve this. The zinc anodes offered by Belmont Metals are industry-leading in quality and consistency, repeatedly reaching the highest levels of qualification for U.S. government and military use.

Whether you’re in charge of a single ship or an entire fleet, reach out to Belmont to find a solution that works for you.