What is zinc,zinc casting and zinc plating

ZINC:A bluish-white, metallic chemical element, usually found in combination such as in the zinc rich epoxy primer,used as a protective coating for iron, as a constituent in various alloys, as an electrode in electric batteries, and in the form of salts in medicines.  Symbol Zn atomic weight = 65.38 atomic number = 30. Melts at 419.5 degrees C, or approx. 790 degrees F.

ZINC CASTING:Zinc in a molten state is poured into a form and allowed to solidify and form the desired part configuration.  The zinc material used in this process is sometimes a poor quality alloy of zinc and can cause outgassing problems.  If the molten zinc or zinc alloy cools too rapidly while it is injected into the mold form it may cause partial solidification which in turn may produce air entrapment that will cause outgassing and/or blistering when the entrapped air expands during the heated cure cycle of the coating process.

ZINC PLATING:Many types of zinc plating surfaces are available in a variety of thicknesses.  Some will readily accept the organic coating and some will not.  The zinc material itself generally does not cause any problems but watch out for the brighteners, wax seals, and other products that are used to prolong the time in which oxidation of the zinc finish occurs.

The application of any zinc coating as a base coat prior to the application of an organic coating provides sacrificial protection as well as the barrier protection that is given by the organic topcoat.  This type of additional protection is also offered by the application of aluminum and zinc by metal spray.  It is important to communicate to the zinc plater or metal supplier that you intend to pretreat and apply an organic coating to the surface.