Page 70: of Maritime Reporter Magazine (March 1998)

MARINE PAINTS & COATINGS

Drew Marine and Tectyl

Team Up To Fight Corrosion

Drew Marine and Tectyl

Industrial Products have joined forces to combat the corrosion of ballast tanks aboard larger ves- sels. Together they have designed

Drewgard WB, a water-based coat- ing that is light in color, easily applied and results in an air dry wax/polymer sulfonate emulsion finish that deters corrosion. The dried coating bonds directly with the metal surface forming a hard film-like barrier, yet it remains flexible and reportedly will not crack.

Circle 16 on Reader Service Card

Monopol Group Releases

Antifouling Paint

The Monopol Group recently introduced Biomarine, an environ- mentally friendly, anti-fouling paint to protect the hulls of ships against parasitic organisms. Its formula is based on specific acrylic ifc

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CRUZAN

DIVERSE iNcqyf

MIL 330 Strand Street • Frederiksted, St. Croix • U.S. Virgin Islands 00840

DON'T WEAR OUT YOUR WELCOME

Dockside is no place to spend too much time. To stay on schedule, call on Cruzan

Divers for a complete range of underwater services. Cruzan Divers offers inspections, nondestructive testing, hull cleaning, repairs, maintenance, prop polishing and a variety of ship services. Complete services are offered at several convenient locations on St.

Croix and mobilization to other areas in the Caribbean can usually happen overnight. Cruzan Divers. We're always happy to see you leave. • Written reports with each service • Video/Photographic documentation • NDT testing through protective coating • Propeller polishing and maintenance -ABS & DNV Certified

St. Croix: 1-800-352-0107

U. 5. Mainland: 1-800-577-4629 email: [email protected]

Circle 327 on Reader Service Card "The SeaLion handles currents with ease and is perfect for difficult jobs requiring long cable lengths of up to 1,000 ft

It features a six motor, variable speed, reversible propulsion system, a CCD color camera and a 13" topside color monitor.

The SeaOtter, a version designed for less extreme conditions, is also available."

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Vj Video resins which are transformed into a self-polishing polymer.

Biomarine reportedly repels organisms without killing them. It can be applied to various types of materials including steel, cast iron, aluminum, polyester, wood and zinc.

Circle 8 on Reader Service Card

ABS Warns of

Microbial Generated

Corrosion and Pitting

A hyperactive bacteria found in most crude oils, sludges and seaweed is reportedly the most likely cause of microbial attachment to a ship's hull, and subsequent damage due to their corrosive natures.

Untreated, these small pits grow into holes that can lead to oil leaking directly into water- ways. If the vessel is double- hulled, the oil will then leak into the void between hulls and create a potentially explosive situation.

A 150,000-dwt tanker experi- enced 2 mm and 3 mm corro- sion pits in certain areas in only two years on its cargo- tank bottom plating.

Microbial-Influenced-Corrosion (MIC) can result from either settled water on the bottom of oil tanks or it can also exist in water droplets condensing from the crude oil itself in con- centrations of up to 10 million cells per cubic mm in the set- tled water.

The bacteria will attach itself to rough surface areas such as weld or scratches. The strate- gy for new tankers can include better washing of the crude oil tanks and better bottom-drain- ing designs.

Consideration should be given to coating the entire internal surface of the cargo oil tank, or possibly coating the cargo oil tank bottom plating and all of the associated struc- tural members up to a range of 100-500 mm high with a lighter color, bacteria resistant epoxy coating.

In addition, the bottom plat- ing thickness can be increased to accommodate higher corro- sion rates.

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