Would like to hear opinions on whether plasma and flame (or other thermal methods) deposited coatings, of the ceramic and cermet type, or of the polymeric type, have any markedly better resistance to corrosion than a more traditional primer and topcoat coating. Specifically, we have a product which will spend years submerged in fresh water, and I’ve always been of the opinion that any type of coating on mild steel in such conditions will eventually fail due to corrosion (crevice corrosion?) along the bond line at any edges/pinholes in the coatings. Is there anything special about the fancy thermal deposition techniques that would improve the situation, or are there formulations that somehow durably cathodically protect the steel?