primers, antifoulants , and tie-coats. In this report, specification recom- 

 mendations should be strictly observed. 



Epoxy paints in general are recommended for all parts of the plant 

 except for flexible surfaces. Highly resistant metals, such as titanium, 

 may not require corrosion protection by painting, if properly isolated from 

 other metals and if antifouling protection is not needed. For the pumps, 

 neoprene coatings are recommended in areas of high erosion. Aluminum sur- 

 faces must have a tested, chromate-containing primer. 



Good surface preparation prior to painting is required, and abrasive 

 blasting is recommended. Steel must be abraded to a coarser finish than 

 aluminum; either should be painted almost immediately after blasting. 



FIBER-REINFORCED PLASTICS 



One candidate material for the OTEC power plant cold seawater pipe is 

 fiber-reinforced plastic (FRP) . A single large FRP pipe has been proposed" 

 to provide the quantity of cold seawater necessary for the operating 

 requirements of the power plant. The pipe could be manufactured in 60-ft 

 lengths, and the total length of the pipe might extend to 4000 ft. 



FRP is a generic term which refers to organic matrices reinforced 

 with fibrous materials. The low-cost, high-strength characteristics make 

 glass the most widely used fiber in fabrication of FRP structures, and the 

 information contained herein is based on the use of glass fiber as the 

 reinforcing material. The important resins utilized are polyesters, 

 epoxies, phenolics, and f uranes . 



Two grades of glass are used: "C" and "E." C glass (chemical grade) 

 is treated to increase its resistance to acid and chemical attack; it is 

 normally used as the surfacing veil or inner liner of equipment. E glass 

 (electrical grade) is applied over the C glass inner liner to build 

 strength into the structure. The strength of FRP structures is a function 

 of glass content. 



Large FRP structures are manufactured by a hand lay-up or a filament- 

 winding process. In a typical hand lay-up method, a mandrel is coated with 

 resin, and C glass is embedded in the resin to obtain a resin-rich inner 

 layer of specified thickness. Additional layers of resin and resin- 

 impregnated E glass mats are applied over the inner layer to build strength 



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