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COATINGS

Protecting your rudder from the start Coatings play central role in reducing your GHG emissions

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avitation corrosion damage on the rudders is fairly common and expensive, no matter what type of vessel you operate. Belgium-based Hydrex NV says this is due to the rudder not being properly protected against cavitation and the resulting erosion and corrosion damage. Hydrex says its Ecospeed coating is a perfect solution to protect against this costly problem for both newbuild vessels and vessels of all shapes and sizes that have been in service. In recent months, for example, the rudders of several types of vessels were given an Ecoshield protective coating at shipyards in China, the U.S., Poland and the U.K. These vessels include three container ships, an oil tanker, a tug and a vehicle carrier. What makes Ecospeed unique is that it contains a high concentration of embedded glass platelets. It has a very low amount of volatile organic compounds (VOC) and is typically applied in two coats of 500 Âľm dft. The coating derives its excellent anti-corrosive properties from its relatively high film thickness and the presence of glass platelets, which act as an impermeable barrier. It is extremely durable, making it perfectly suited for regular in-water surface treatment. Hydrex says that tests carried out in a flow channel in Grenoble confirmed that Ecoshield performs extremely well under severe cavitation. The coating prevents corrosion damage from reoccurring on an existing ship or can protect the rudder of a newbuild

28 MARINE LOG February 2014

Compiled by Marine Log Staff

vessel against cavitation and corrosion damage from the very start for the life of the vessel.

Protection from the start Protection of your rudders is best begun at the newbuild phase. When a vessel comes into dry dock, maintenance of its stern area, especially cavitation damage repair, can take a long time. There are strict procedures concerning blasting, painting, welding and propeller and stern tube seal work. Painting is then assigned to the end of the schedule. As a consequence it may be rushed or not get done at all or else prolongs the stay in dry dock. With an Ecoshield application one can avoid these problems from day one because the underwater gear will not need to be repainted during future dry dockings. Ecoshield will remain intact for the lifetime of the vessel and is guaranteed for ten years. At the most, quick and easy touch-ups amounting to less than 1% of the surface area will be required. Planning the maintenance of the vessel’s stern area therefore becomes much easier.

fix the surface first Subsea Industries, a Hydrex company, has just unveiled Ecofix, a complementary product to Ecoshield for filling and building up a corroded and pitted steel surface to its original form prior to recoating with Ecoshield. Ecofix is as tough as the steel itself, machinable,


February 2014 Marine Log Magazine