Zinc, a natural, healthy, and abundant element was first used in construction in 79 AD; thus, its characteristics as a well-suited corrosion protective coating for iron and steel products has long been known. The 24th most abundant element in the Earths crust, zinc is naturally present in rocks, soil, air, water, and the biosphere, as well as in plants, animals, and humans. In fact, zinc is essential to life as all organisms require it to survive and complete normal physiological functions.
Today, more than 13 million tons of zinc are produced annually worldwide, 70% from mined ores, and 30% from recycled sources. More than half of the annual production is used in zinc coatings to protect steel from corrosion. Because zinc is an infinitely recyclable material, the level of recycling increases each year, and currently 80% of the zinc available for recycling is indeed reclaimed. However, because of zincs excellent field performance as a corrosion protection coating, it often remains in service for generations before recycling.
There are a number of zinc coatings which are often generically termed galvanizing, but each has unique characteristics. These characteristics not only affect applicability, but also economics and performance in the environment. The method of application, adhesion to the base metal, hardness, corrosion resistance, and thickness of each zinc coating varies. This practical aid examines the following zinc coatings: batch hot-dip galvanizing, continuous sheet galvanizing, zinc painting, zinc spray metallizing, mechanical plating, electro-galvanizing, and zinc plating; to help architects, engineers, and other specifiers assess and select the most suitable zinc coating for corrosion protection.
This practical aid was designed to assist specifiers with the selection of zinc coatings for corrosion protection by discusses the various zinc coatings and their characteristics. Revised in 2011, the guide is 12 pages and includes graphs and pictures.
The AGA has translated this publication into Spanish. This publication is only available to download as a PDF.
Copies of this resource are available for purchase. Architects, engineers, and other specifiers in North America may request a single copy of any publication at no charge, unless otherwise indicated. Multiple copies require a $25.00 (US funds) minimum order, plus shipping and handling. Prepayment is required. (Member galvanizers are not eligible for complimentary printed copies and require a $75.00 minimum order.) Non-member galvanizers must contact the AGA directly at 720-361-4483.