Organic zinc-rich primers Protective

In both organic zinc-rich and inorganic zinc-rich primers the duration of cathodic protection is finite and the effects of polarization of zinc and the production of zinc corrosion product on the surface results in a change of protection mechanism from... 

As indicated in Table 10.18, a zinc-rich primer is often recommended. It can be an organic zinc-epoxy or an inorganic zinc-ethyl-silicate primer. Zinc-rich primers are also used as so-called shop primers, or prefabrication primers, for temporary protection of semi-manufactured steel goods. After fabrication, e.g. of welded steel structures, the shop primer surface must be cleaned (degreased), and possible shop primer defects and weld joints have to be blast cleaned and coated with a primer before the whole structure is painted. Iron oxide is also used as a pigment in some shop primers. These must not be overpainted with a zinc-rich paint. 

Hare, C, Steele, M, Collins, SP. 2001. Zinc Loadings, Cathodic Protection, and Post-Cathodic Protective Mechanisms in Organic Zinc-Rich Metal Primers. J. Protect. Coat. Linings, 54. 

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