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Circle 234 on Reader Service Card oductivity starts with Performance Line ration Products You expect your hard- working engines to deliver. Now, you can rely on i Filtration Services to make you get where yc going. MPL is designed to maximize performance and minimize engine wear. MPL is available for all major marine diesel engines applications (EMD, Detroit Diesel, Deere, CAT, Cummins, Lugger, Volvo Penta). To find out more about MPL brand filters, write to. arine 402 BNA Drive, Suite 500 NasMe,TN 37217 mmi ssanne raanwji Manager LEEVAC SHIPYARDS, INC. We Make It Happen! 1 NEW CONSTRUCTION CONVERSIONS REPAIRS DRYDOCKING GAMBLING VESSELS INLAND PUSHBOATS SUPPLY BOATS SEISMIC VESSELS BARGES SPECIALTY VESSELS L Hwy. 90 East P.O. Box 1190 Jennings, LA 70546 PH. 318/824-2210 FAX 318/824-2970 Circle 254 on Reader Service Card J Circle 265 on Reader Service Card MCELROY DECK EQUIPMENT ENGINEERED TO PERFORM MANUFACTURED TO LAST P.O. BOX 4454 BILOXI, MISSISSIPPI 39535-4454 |60l|896-3736 CAPSTANS TOW WINCHES McElroy is ready to design, manufacture and deliver any type deck equipment your requirements call for. The International WorkBoat Show! jjL Nov. 30 - Dec. 2, 1995 Ernest N. Morial Convention Center New Orleans, LA (ISA Registration Hotline Pre-register to visit by Nov. 2, 1995 and get in FREE. Tel: 1-800-454-3007 Fax:1-800-454-3002 If you're buying or selling products and services for the shatlowdraft fleet, you can reach the commercial marine industry at the 17th annual International WorkBoat Show. Your Point of Access to Products & Technology for the Shallowdraft Fleet • The International WorkBoat Show More than 14,000 marine professionals will have access to over 900 booths of important resources for all segments of the work boat industry. • Tugs & Towboats • Passenger Vessels • Oil Supply Vessels • Utility Boats • Barges • Military & Patrol Vessels • Shoreside Services • Casino Boats Marine Contractors ^ Fishing Boats Over 850 booths are already committed, but there's still plenty of excellent exhibit space available. For more information on exhibiting, call or fax today: Phone: 207-842-5508 • Fax: 207-842-5509 Circle 239 on Reader Service Card October, 1995 percent acrylic water-based emulsion enamel for use over primed metal surfaces. Epoxy Coatings Epoxy coatings for marine use fall into two broad categories: epoxy esters (single package materials) and catalyzed epoxies (two package materials). Epoxy esters are alkyd or vegetable oil modified epoxies. They have enhanced chemi- cal resistance and durability as compared with conventional alkyds. These types of epoxies see limited use in marine coating specifications. Two-component catalyzed epoxies, however, are widely used as protective coatings in marine environments. One of the most widely used epoxies in marine coating work is MIL-P-24441- Paint, epoxy-polyamide. Polyure thanes Polyurethanes can be divided into two catego- ries: single package moisture cure urethanes; and two-package polyisocynate-polyol polyure- thanes. The single pack coatings contain mois- ture curing polyisocynate terminated prepolymers. The two-package urethanes con- sist of two parts which, when mixed together, cross link to form the cured polyurethane coat- ing. Urethanes are generally used as top coats over more economical primers such as epoxies. Vinyl Coatings Vinyl coatings can be divided into the follow- ing categories: polyvinyl butyral; polyvinyl chlo- ride; and polyvinyl acetate. Polyvinyl butyral coatings are used as wash primers to inhibit corrosion and promote adhe- sion. These coatings contain basic zinc chromate and phosphoric acid. Chromates contain chro- mium, which is on the Environmental Protection Agency's (EPA) HAPS list. Polyvinyl chloride and polyvinyl acetate coat- ings are thermoplastic coatings that dry by sol- vent evaporation into very durable films, with excellent performance in corrosive and marine environments. Vinyl copolymers are the back- bone for many effective anti-foulant coatings. Chlorinated Rubber Coatings Chlorinated rubber coatings are thermoplas- tic coatings that dry by solvent evaporation. They have excellent chemical and moisture re- sistance, and have enjoyed significant success in marine environments. Zinc Rich Coatings Zinc rich primers are classified in SSPC- PAINT 20. Essentially, they can be divided into two broad categories: inorganic and organic zinc rich. The terms inorganic and organic refer to the resin or binder type rather than the zinc metal. Type I-C inorganic self-curing vehicles are of particular interest due to their wide use in coating steel plates in marine environments. This type of zinc-rich coating is based on an ethyl silicate resin, and cures by a reaction with atmospheric moisture, thereby providing ca- thodic protection to steel surfaces. Type IA inorganic zinc rich coatings are post- cured with a separate wash solution which is usually mildly acidic. Type II zinc rich coatings employ an organic vehicle that may be an epoxy, urethane, chlorinated rubber, styrene, or vinyl. Organic zinc rich coatings may have a zinc dust content of 80-95 percent as opposed to inorganic zinc rich coatings which are above 75 percent with a nominal value of 85 percent. In spite of the difference in zinc loading, inorganic materials offer longer cathodic protection due to zinc particle contact within the zinc/silicate matrix. The organic zinc rich coatings are less demand- ing with respect to surface preparations, and develop better adhesion. While more demand- ing than their solvent based counterparts with respect to surface preparation, type IB inor- ganic self-curing, water-reducible zinc rich coat- 35
