Essential Strategies for Offshore Corrosion Prevention & Control

The best offense is a great defense. While this phrase is most commonly used in reference to sports strategies, it also rings true in the field of offshore corrosion prevention. Think about it: the best way to fight against corrosion is to prevent it from happening in the first place.

At Tesla NanoCoatings, that notion is exactly what we’ve dedicated our work to. In today’s article, we’ll be going over a few of the reasons that we find our approach to be the most strategic- and how our customers find it to be the most effective.

Understanding Offshore Corrosion

The reason that our approach works as well as it does has to do with the nature of corrosion and how it spreads. In an offshore or marine environment, there are countless elements battering a given steel structure: saltwater, extreme temperatures, high impacts, and the list goes on. In terms of corrosion risk, a metal structure in an offshore setting is getting attacked from all sides at all times.

The thing to consider with corrosion is that is has to start somewhere. For it to inflict any degree of damage to a metal part, it has to make that initial point of contact. On a bare piece of metal, a surface oxide could build in just a matter of hours, then that surface oxide can quickly penetrate further into the material. To prevent offshore corrosion damage, most owners choose to guard their metal structures with a protective coating.

Select Your Protective Coating Wisely

Protective coatings act as the first and final line of defense for offshore metal structures, so failure is not an option. Despite this, the 3-step coatings that have become the industry standard have been shown to fail in as little as just 6 months.

These coatings use an epoxy base which is combined with additives like zinc for cathodic protection, which we’ll be going over shortly. While it may sound good on paper and perform well enough in lab tests, this formula has a fatal flaw. Those same zinc particles that are added to the mix act as bond-breakers which reduce the strength of the epoxy overall, making the coating more susceptible to physical damage from impact. This translates to quicker coating failures; more frequent maintenance and subsequent downtime; and a risk of corrosion damage that’s too close for comfort.

With that type of performance being the industry standard, it is critical to perform extensive research before selecting the right coating to protect your offshore structures. Proper coating selection should be a key part of your strategy, as its performance can make or break the effectiveness of your plan. If you need some help getting pointed in the right direction, you can start by checking out our TESLAN® line.

Ensure Cathodic Protection

After that explanation, you may be wondering why a protective coating wouldn’t just omit zinc altogether. Some coatings do, but it is usually substituted with another metallic agent, like aluminum dust, that can have a similar effect. Other methods, like thermal sprayed aluminum, nix the zinc but come at a significantly higher material and application cost. Despite the way it reduces the impact resistance and adhesion of an epoxy coating, a zinc additive is one of the most effective ways to provide cathodic protection to metal structures offshore.

Simply put, cathodic protection is what prevents oxidation from occurring, even for a short time after a physical coating failure. The zinc acts as a sacrificial anode, giving up its own electrons to react with surrounding saltwater and air in place of the steel’s electrons. Cathodic protection is an essential tool to preserve metal structures, and should never be overlooked when developing a life cycle strategy.

So, is there a balance to be struck between cathodic protection and impact resistance?

There certainly is- and today, Tesla NanoCoatings is the only company to expertly navigate that balance. The key lies in the utilization of carbon nanotubes (CNTs), something that only a handful of companies around the globe have managed to do. In essence, CNTs reinforce our epoxy coatings like rebar reinforces concrete, giving them the added strength they need to withstand the offshore environment. At the same time, they function as an electron transfer network for the sacrificial zinc anodes, amplifying cathodic protection to its maximum potential. For a more in-depth explanation, be sure to visit our blog on The Function of Carbon Nanotubes in offshore corrosion prevention.

Establish A Monitoring and Maintenance Plan

One more strategy that is truly essential to the longevity of your offshore corrosion prevention plan is to develop a regular inspection and maintenance schedule. By routinely inspecting and reporting on the condition of an existing coating, it becomes much easier to identify problem areas and address issues before they grow in severity. Here are a few factors to take into consideration when developing an inspection and maintenance strategy.

Inspection Frequency

Determining the frequency of your inspection schedule is a great place to start. You can always begin with a moderate schedule of quarterly or biannual checks, then increase or decrease frequency as needed.

Key Inspection Points

Where is corrosion most likely to begin on your structure? Keep an eye on these locations, so that if corrosion does occur, it can be dealt with quickly.

Maintenance Methods

When maintenance is needed, how will you approach it? Consider what would be least disruptive to your regular operations.

Maintenance Materials

The materials you use can greatly influence maintenance-related downtime. Select materials that minimize application time and have a longer life cycle, like TESLAN® Pit Filler and TESLAN® coatings.

Offshore corrosion prevention has many facets to consider, but with our guide you can focus on those that are most essential. By selecting the right coating, ensuring cathodic protection, and establishing an effective maintenance plan, you can maximize the chances of your strategy’s success.