Table 6. 



Surface Preparation Standards for Abrasively 

 Blasted Steel 



Surface Finish 



NACE 

 Standard 

 (Ref 10) 



SSPC 

 Standard 

 (Ref 7) 



SSPC/SIS 



Visual 

 Standard 

 (Ref 7) 



White Metal Blast 

 Near-White Blast 

 Commercial Blast 

 Brush-Off Blast 



1 

 2 

 3 

 4 



5 



10 



6 



7 



CSa3 



CSa2-l/2 



CSa2 



CSal 



Table 7. Coatings Commonly Used on Steel Tower Structures 



Generic Type 



Minimum Surface 

 Preparation 

 Recommended 



Ease of Repair 

 and Topcoating 



Important 

 Properties 



Alkyd 



Commercial, but 



easy 



Wets surface well; 





tool or brush- 





weathers well; 





off may be OK 





protection good in 

 most environments. 



Vinyl 



Commercial or 



easy 



Protection good in 





near white 





all environments. 



Chlorinated 



Commercial or 



easy 



Fast curing; pro- 



Rubber 



near white 





tection good in 

 all environments. 



Epoxy-Polyamide 



Commercial 



difficult" 



Excellent protec- 

 tion; chalks freely 

 in sunlight. 



Urethane 



Commercial or 



difficulty- 



Excellent protec- 





near white 





tion; aliphatic 

 urethanes have 

 excellent exterior 

 weathering. 



Inorganic Zinc 



Near white or 



difficult" 



Excellent abrasion 





white 





resistance; used 

 as preconstruction 

 primers. 



Organic Zinc 



Commercial or 



varies 



More easily top- 





near white 





coated than inor- 

 ganic zincs. 



"Special precautions must be taken in topcoating chemically 

 curing coatings . 



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