(3) Modified Alkyds . Modified alkyds have additional resins added 

 (such as ester gum, phenolic, styrene, vinyl, acrylic and chlorinated rubber) 

 to improve properties such as weather resistance and corrosion resistance. 

 They may be used for some coastal structures, however, because of the limited 

 corrosion resistance of alkyds, immersion service or exposure to corrosive 

 environments is not recommended. 



(4) Acrylic (Solvent Base) . Acrylic coatings may be formulated 

 as solvent-base or as water-base materials. The solvent-base coatings 

 are composed of copolymer acrylic resins in an aliphatic hydrocarbon 

 solvent. They cure by evaporation of solvents and in some respects 

 possess the toughness and corrosion resistance of a baked enamel. Acrylics 

 have good resistance to general weathering. They have excellent gloss 

 retention and color stability. Their resistance to marine atmospheres and 

 corrosive environments is good. They have good impact resistance and fair 

 heat resistance. Acrylics may be used as topcoats for epoxy, modified 

 alkyd, zinc rich and universal primer. They are not recommended for 

 immersion. 



(5) Acrylic (Water Base) . The water-based acrylic products are 

 widely used for masonry, stucco, or wood for both interior or exterior 

 application. They are also used to a limited extent for metals. Because 

 they are water based they are nonflammable and may be used in fire hazard 

 areas. They are quick drying and may be easily cleaned with water. Acrylic 

 water-base coatings have excellent color retention, good flexibility and 

 toughness, and are easy to repair. They have only fair corrosion resistance. 



Acrylic resins are used in conjunction with other resins to improve 

 color stability and general weathering resistance. 



(6) Chlorinated Rubber . Chlorinated rubber coatings are composed 

 of rubber polymers chemically treated with chlorine in a blend of 

 solvents. They cure rapidly by solvent evaporation. Chlorinated rubber 

 coatings have fair to good corrosion resistance to marine and chemical 

 corrosion. They resist most dilute acids, alkalies and salts and have fair 

 weathering resistance and color stability. They are suitable for immersion 

 in salt and fresh water to 49° Celsius (120° Fahrenheit) . Chlorinated 

 rubber coatings have fair abrasion and impact resistance but possess only 

 poor resistance to organic solvents. 



(7) Coal-Tar Coatings . 



(a) Mastics and Coal-Tar Cutbacks . Coal tar is a byproduct 

 of the coal coke industry and has outstanding water resistance. For this 

 reason it has been found to be an excellent coating material for use on 

 many coastal structures. Its high resistance to moisture makes it useful 

 for immersion or for the splash zone service. It is one of the finest 

 coating materials for resistance to water or moisture. For this reason, it 

 is frequently used for protecting steel or concrete in immersion. Coal-tar 

 products are usually applied by spray because of their heavy consistency, 

 but touchup is frequently handled by brush. Additional thinner may be 

 added when the coating is applied by brush. 



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