Corrosion passivation of tugboat Adriaan

Kotug is a leading towing company offering its services to ports and terminals worldwide. In March 2016, tug Adriaan, the oldest tug in Kotug’s fleet and one of the first tugs the company operated in the 1950s, was docked at Padmos Yard, Netherlands. nC Corrosion Passivation was one of the favorite applications during this docking, as this technique has proven itself aboard the Adriaan since the first application of Corrosion Passivator in 2011.

Because the Adriaan was in need of steel renewal in several areas of the hull, there was an opportunity to stop and prevent corrosion in hard-to-reach places in the stern. Kotug’s project manager chose corrosion passivation with nC Corrosion Passivator. We applied the corrosion passivator to inside hull of tug Adriaan.

The photo shows the inside of the aft peak of tug Adriaan, as it was found in the yard. No blasting, sanding, chipping or whatever treatment was done before this photo was taken. This is just before nC Marine began treating the hull structure with nC Corrosion Passivator.

The photo shows the application of nC Corrosion Passivator by brushing. Although the Corrosion Passivator can be floated, it is also great for brushing, rolling or spraying. Because nC Corrosion Passivator – Fluid is non-toxic, does not emit flammable gases and does not cause dizziness or drowsiness, it is a perfect technique to use in confined or small spaces, especially near or in areas where people eat, sleep and live.

nC Corrosion Passivator is delivered to the metal by a wool grease-based carrier. This allows the active particles to settle into the metal and remain active without being stopped by a drying coating. The carrier holds the active particles in place long enough to do their work of decalcification and passivation. Especially in ballast water tank environments, where (salt) water floats in and out and flushes, it is very important to use the right carrier to resist flushing and keep particles in place.

Unexpectedly, the deck plates were already welded in, so the space between aft peak and rudder house is no longer accessible…. we have to open it up again with a flame cutter. Or not? This is where the advantage of nC Corrosion Passivator comes in: You can apply the technique by floating, as shown in the photos.

Pour in the calculated amount of nC Corrosion Passivator. The calculation for the correct amount used is based on the number of m² (surfaces, spot repairs) and/or m³ (ballast water tanks, voids, peaks, internal structures). Usually a ratio of 1 liter per m³ is sufficient.

Then the tank can be filled with water. You can use sea water or fresh water, it doesn’t matter. Allow for a maximum rise rate of 20 cm per minute. Be sure to reach the tank tops completely. If possible, we place air hoses by magnets at the highest point of the tank so that the air can escape freely without forming air pockets in the tank. After this, the tank can be drained. nC Corrosion Passivator – Fluid itself is harmless to aquatic life. The surface you are looking at will dry within a few weeks.

Some advantages of nC Corrosion Passivator:

• Displaces water, no drying required before or after.
• Corrosion passivation, protected metal for 5 to 15 years, depending on fresh or salt water and environmental conditions
• No cost or time for sandblasting, coating, curing.