Relationship Between Coatings and Anodes
The Relationship Between Coatings and Anodes
Sacrificial block anodes protect a vessel's hull by dissolving into the seawater, sacrificing themselves to prevent rusting. The speed at which an anode dissolves depends entirely on how much bare steel is exposed to the water. On a standard paint system, micro-cracks and water absorption force the anodes to work constantly.
Our Cathodic Duplex System acts as an impenetrable shield (certified to survive 4000 hours of saltwater immersion under ISO 12944 IM3) [ISO 12944-2, ISO 12944-6]. It seals off the hull plates, reducing the workload on sacrificial anodes.
While our coating provides elite protection for the steel hull, block anodes must still be used to protect the unpaintable & high-risk areas of the vessel:
▶️ Galvanic Protection for Mixed Metals:
The bronze propeller, stainless steel shaft, and rudder fittings create a natural battery in saltwater. This localized electrical current will aggressively attack steel welds near the stern. Sacrificial anodes must be placed here, to neutralize this galvanic reaction.
▶️ Stray Current Defense in Harbours:
When docked & connected to shore power, stray electrical currents leak from the pier or nearby vessels. Block anodes act as a grounding sponge, absorbing this electrical energy before it attempts to stress or pierce the PU topcoat.
▶️ Grounding and Anchor Chain Scrapes:
Heavy physical impacts(such as anchor chain scraping, ice, or rubbing against concrete piers) may gouge through some Coatings. Block anodes provide the electrical output needed to protect these scraped areas until the ship's next dry-dock cycle.
By combining our Duplex Coating System with traditional block anodes, fleet owners achieve a highly optimized system:
➡️ Drastically Extended Anode Lifespan:
Because our 24 MPa adhesion coating leaves virtually no steel exposed, your block anodes will dissolve at a fraction of their normal rate. Anodes that usually need replacement every 12 to 24 months can last significantly longer.
➡️ Reduced Dry-Dock Frequency:
Anode depletion is a major reason ships must enter dry-dock. Extending the life of the anodes allows owners to safely extend their dry-dock cycles.
➡️ Dual-Layer Security:
If a collision or scrape were to damage our Extreme 2K topcoat, the 85% active zinc base layer provides localized protection. If the scrape goes all the way to bare steel, the block anodes step in as the final backup shield.
Don't eliminate your sacrificial anodes when applying our system. Instead, view our Duplex System and your block anodes as a team. The coating seals the hull & extends the lifespan of the anodes, while the anodes protect the moving parts and mechanical zones.
Together, they offer the lowest total cost of ownership and the highest level of corrosion protection available in maritime engineering today.
