Laboratory and field tests on several corrosion-resistant primers (conventional red lead, basic lead silico-chromate, self-cure and post-cure inorganic zinc and the zinc-rich phenoxy system) reveal that zinc formulations give superior protection. Post-cure zinc-rich primers were not as satisfactory as self-cure formulations because of the formation of white reaction products on the surface of the post-cure coatings. Standard specifications in California (1973) permit only the use of phenoxy zinc-rich primer. The on-package phenoxy system is much simpler and less previous layers of itself and to adjacent finish coatings in spot repair painting. The phenoxy primer showed no mud-cracking even when multiple passes laid down a 30-mil dry film. The problem of top-coating is eliminated with application is recommended of a vinyl butyral wash coat 0.3 to 0.5 mil thick over the zinc-rich primer before top coating.

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  • Accession Number: 00084780
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 2 1975 12:00AM