List three primers used to prevent corrosion and where they should be used.

Question

What will be an ideal response?

Answer 1

Weld-through coatings: One product that stands out from the other primers is weld- through coatings. These are special zinc-rich primers designed to protect the microscopic voids that form from the welding heat on the inside of the flanges and mating surfaces. These surfaces cannot be reached to properly treat after the panels have been welded together therefore they must be treated with the weld-through coating prior to assembling them.
Self-etching primers: Self-etch primers may be more desirable to use in areas where access is difficult to perform the scrubbing and cleansing tasks that precede the application of the material. They contain phosphoric etching material that neutralizes and etches the surface as it dries thus eliminating the need for using the metal etching chemicals and conversion coatings prior to its application. They are also a zinc-rich material which affords excellent corrosion resistance.
Epoxy primers: The most universal primer available is the two-part epoxy primer, commonly referred to as a 2-k product. It can be applied over a properly prepared or etched bare steel and aluminum substrate and nearly every imaginable surface. When applied over a painted surface it need only be cleaned and abraded first. When applying it over steel or aluminum, the surface must first be abraded and chemically treated and etched.