Zinc Primer Technology Innovations for Improved Performance
The Role of Zinc in Offshore Protection
Anywhere that you may find steel material used in an offshore setting, chances are that its good friend and protector, zinc, is close by. While steel is a remarkably strong material for structural applications like rigs, platforms, and pipelines for offshore oil & gas, its greatest weakness comes in the form of susceptibility to corrosion. While getting rid of surface rust is a relatively easy fix, the true problem arises when that corrosion seeps past the surface and begins eating away at the metal. In an offshore setting, dealing with surface rust before it spreads would require around the clock surveillance and maintenance– and who has the time for that? That’s where zinc comes into play.
As discussed in a previous article, The Synergy of Zinc with Carbon Nanotubes, zinc is a more electrochemically reactive material than steel. So, when a layer of zinc is applied to a steel substrate, it acts as an electron-donating shield that preserves the strength and integrity of the base metal. Although galvanization is an option, most owners and operators are going to opt for the much more cost-effective and maintenance-friendly option of using a protective coating system which utilizes a zinc-rich primer.
Where Traditional Zinc Primers Don’t Stick
Traditional zinc-rich primers sound promising on paper. But what you likely won’t read anywhere else is that the addition of zinc at a level that can actually be effective presents significant mechanical challenges in most epoxy coatings.
Zinc is an effective material for cathodic protection thanks to its electrical conductivity. However, this doesn’t change the fact that the surrounding epoxy is an insulator. In order for electrons to flow freely, the zinc particles dispersed throughout the coating must be in physical contact with one another. The way that most coating manufacturers achieve this is straightforward– they just add a lot of zinc powder to their formula. The problem with doing so is that it results in a high ratio of zinc to epoxy resin. With more particles to hold together and less epoxy to keep the coating in one piece, the increase in cathodic protection comes at the price of mechanical integrity.
With this in mind, zinc solves the issue of cathodic protection, but creates new problems in disrupting the overall strength of an epoxy coating. While this may seem like a Catch 22 at first, Tesla NanoCoatings’ latest zinc primers provide a truly innovative solution that not only remedies the issues, but provides coatings with a never before seen level of strength.
Enhancing Zinc Primers with Carbon Nanotubes
The secret to our sauce is actually no secret at all. At Tesla NanoCoatings, each and every one of our zinc epoxy primers include one component that sets us far above any competition. That component comes in the form of carbon nanotubes (CNTs).
Unlike zinc, which on its own goes wherever gravity tells it to, carbon nanotubes display unique self-aligning properties. As the coating dries, they don’t just sink to the bottom– they find each other and interconnect to create a network that spans the entire area of the protective coating. While the addition of zinc may disrupt the epoxy film, CNTs instead act as a supporting structure. Think of rebar in concrete, only on a nanoscopic scale.
So that solves the issue of the primer’s mechanical strength, but what about its cathodic properties? Almost as if designed for this exact application, CNTs enhance cathodic protection, too. The interwoven network of carbon nanotubes doesn’t just act as a physical support to the epoxy film. It also doubles as a high-speed network across which the coating’s zinc particles can freely donate their electrons before you can even think of blinking an eye. This expansive, fast-travel network for electrons helps keep steel structures protected from the threat of corrosion for years upon years at a time. While most traditional protective coating systems last for only 2-5 years at a time, TESLAN® systems have been recorded to last for 10+ years without any signs of failure.
2×1 Wet Edge™ Technology
While the addition of CNTs has yielded undeniable benefits for our customers the world over– and continues to do so– our team of innovative coatings engineers did not stop there. In our latest white paper, Achieving FM Productivity, we brought exposure to the fact that most offshore owners, operators, and contractors spend a significant portion of their coating application and maintenance time not applying anything at all. Most of the zinc primers and epoxy topcoats on today’s market take multiple coats with hours of dry time in between applications. In addition, nearly a quarter of all time-on-tools (TOT) is spent on washdown operations to remove any contaminants to prepare the surface for the next coating layer. TESLAN® coating systems solve that issue too, saving days worth of application time.
This is made possible through our 2×1 Wet Edge™ technology. This technology facilitates a “wet-on-wet” application process in which a topcoat can be painted almost immediately after the primer has been applied. Not only does this eliminate washdown and dry time between coats altogether; with TESLAN® being only a 2-coat system, the entire application can be completed in just a single site visit.
When it comes to innovations in zinc primers, epoxy topcoats, and the protective coatings industry as a whole, Tesla NanoCoatings proudly leads the charge… no pun intended.
TESLAN®’s capabilities are even more shocking when you consider the status quo. We’ve gathered insights on the last 10 years of offshore fabric maintenance in the Gulf of Mexico– available to you at no cost.
