becomes permanent so that little bare steel is ever exposed. If sig- 

 nificant areas of steel will require spot cleaning and recoating, an 

 alkyd or epoxy-polyamide system that is relatively tolerant of incom- 

 pletely cleaned steel have advantages. Vinyl and chlorinated rubber 

 systems are more easily topcoated than other systems because they are 

 lacquers. Obviously, all significant factors must be considered before 

 an optimum coating and procedure can be chosen for steel antenna towers. 



SUMMARY OF RESULTS AND RECOMMENDATION 



Most of the experimental paints exposed on the antenna positioner 

 at Point Mugu provided excellent protection for 2 years in a marine 

 atmospheric environment. These results correlated well with those from 

 accelerated laboratory (salt-spray) testing. 



After 6 months of field exposure, eight out of nine experimental 

 coatings containing a butyl titanate corrosion-inhibiting agent provided 

 very good protection. The performances of these materials will be 

 monitored periodically so that results can be used in field tests when 

 the opportunity arises. 



The backpack equipment seem too heavy and too underpowered to be 

 practical for field use. Reducing the weight by design change or lighter 

 materials appears infeasible. The use of an air compressor on the 

 ground with hose lines connected to the backpack appears to be a feasi- 

 ble alternative for this equipment. 



It is recommended that the coatings and cleaning methods developed 

 in this investigation be field-tested on a full scale if the opportunity 

 arises. 



ACKNOWLEDGMENTS 



The assistance of CEL personnel Messrs. R. Staples and L. Underbakke 

 in preparing the experimental specimens is gratefully acknowledged. 



REFERENCES 



1. Civil Engineering Laboratory. Technical Note N-1516: Repair systems 

 for damaged coatings on Navy antenna towers - Part 1, by L. K. Schwab 

 and R. W. Drisko. Port Hueneme, Calif., Mar 1978. 



2. General Service Administration. Federal Test Method Standard 141a: 

 Paint, varnish, lacquer, and related materials; methods of inspection, 

 sampling, and testing. Washington, D.C., Sep 1965. 



3. Naval Civil Engineering Laboratory. Technical Report R-786: Per- 

 formance of ten generic coatings during 15 years of exposure, by C. V. 

 Brouillette and A. F. Curry. Port Hueneme, Calif., Apr 1973. 



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