Technical Library

Hot-Dip Galvanizing for Corrosion Protection: A Specifier’s Guide

Corrosion and damage caused by corrosion is costly. Hot-dip galvanized steel can help combat corrosion. Learn about the properties and performance of HDG steel and how galvanizing can enhance a project.

Design of Products to be Hot-Dip Galvanized After Fabrication

Achieving a high-quality hot-dip galvanized coating starts with proper design. Learn how to incorporate the best design practices that promote higher quality products with reduced cost and shorter turnaround times.

Inspection of Hot-Dip Galvanized Steel Products

Inspection of hot-dip galvanized steel is required to confirm applicable specification requirements are in compliance for optimal durability and performance of the galvanized product. Learn about the HDG inspection process.

Duplex Systems: Painting Over Hot-Dip Galvanized Steel

Painting over hot-dip galvanized steel (duplex system) can provide benefits beyond just achieving the desire aesthetics. Understand how proper surface preparation is important to the success of the paint or powder coating adhesion.

Hot-Dip Galvanizing Costs Less, Lasts Longer

When selecting a corrosion protection system for a given project, it is paramount to consider more than just the initial cost. Taking into account the life-cycle cost of maintaining a corrosion protection system provides a more accurate prediction of the project’s impact on future generations.

Hot-Dip Galvanized Coating Appearance

HDG steel may have a variety of different initial appearances, including bright and shiny, dull, spangled, mottled, or matte gray. Learn more about the causes and concerns relating to HDG steel’s appearance.

Life-Cycle Cost Calculator

The Life-Cycle Cost Calculator (LCCC) allows you to input specific project data to compare the initial and total cost (initial + maintenance) of more than 30 steel corrosion protection systems (paint, metallizing) compared to hot-dip galvanizing.

Zinc Coating Life Predictor

The Zinc Coating Life Predictor (ZCLP) is a tool that estimates the corrosion rate of zinc in various environments using statistical methods, neural network technology, and an extensive worldwide corrosion database.

Progressive Dip Calculator

The Progressive Dip Calculator is a tool used to confirm whether an article of known dimensions can be progressive dip galvanized within a galvanizing kettle of known dimensions by modeling the article as a 3-dimensional box.

How long does HDG last?

The corrosion resistance of zinc coatings is proportional to the thickness of the coating but varies with the environmental exposure conditions. Each environment affects hot-dip galvanizing differently based on a unique set of corrosion variables.

Metals in contact with HDG

The hot-dip galvanized coating is primarily comprised of zinc and zinc alloys and is sometimes placed in contact with different metals. This creates the possibility for galvanic corrosion that depends on the position of the other metal relative to zinc in the galvanic series, and to a lesser degree on the relative size of the surface area of the two metals in contact.

Can you paint over HDG?

Though many specifiers are familiar with specifying one type of corrosion protection or another, few realize the intrinsic value of utilizing two corrosion protection systems together, known as a duplex system. A duplex system is formed by painting or powder coating over hot- dip galvanized steel.

Button/Link to Knowledgebase

Browse the AGA’s library of FAQs published as Knowledgebase articles on galvanizeit.org.

Button/Link to contact AGA’s Technical Department

Contact the AGA’s Technical Department for specific questions about your project and the performance of HDG steel.

In-Person

Our in-person Galvanize It! seminar is the best way to earn free CEU’s and learn about hot-dip galvanizing because you can meet with a galvanizing representative face-to-face who will address any questions or concerns immediately. Sign up for a seminar to be presented at your office and lunch is on us!

Online

If an in-person seminar will not work for you or your office, we offer our Galvanize It! seminar series online, which is a great alternative. The online seminars allow you to take the courses at your convenience and are followed by a short quiz.

Webinar

The AGA’s Galvanize It! seminar series is also offered as a webinar presented by an AGA staff member. Webinar attendees will learn about the various aspects of hot-dip galvanizing followed by live Q&A to answer specific questions. All webinar versions are approved for 1.0 LUs (HSW) / PDH through AIA and RCEP.

Hot-Dip Galvanizing

General article detailing the various sustainability resources offered by the AGA as well as the steel (AISI & AISC) and zinc industry (IZA).

HDG Steel Environmental Product Declaration (EPD)

The AGA has developed an industry-wide EPD for hot-dip galvanized steel after fabrication hot-rolled sections, plate, and hollow structural sections.

American Institute of Steel Construction (AISC) Sustainability Resources

Steel is the most recycled material on the planet. Learn how the structural steel industry is committed to sustainability and view AISC’s sustainability resources.

American Iron & Steel Institute (AISI) Sustainability Resources

The American steel industry is the cleanest and most energy efficient of the leading steel industries in the world. Learn how American steel producers are committed to sustainability.

International Zinc Association (IZA) Sustainability Resources

The zinc industry is committed to sustainability and works to ensure that its production and use are in harmony with the natural environment and the needs of society, now and in the future.

Inspection Course

The AGA has created an online, on-demand inspection course that will train individuals on the proper inspection techniques and requirements for hot-dip galvanized steel products. Anyone who completes the course, and passes the test (80% or better) will receive a printable Certificate of Completion and will be listed on the AGA website.

Inspection App

The AGA has created a comprehensive mobile app to aid in the inspection of hot-dip galvanized steel. The app is a visual guide to identifying various surface conditions present after hot-dip galvanizing. The app is available for free download in both the Apple and Google Play stores.

Touch-up & Repair Guide

The AGA has compiled a list of various manufacturers and products for the proper touch- up and repair of hot-dip galvanized structures.

General Hot-Dip Galvanizing vs. Continuous Sheet Galvanizing

This one-page handout is a comprehensive side-by-side comparison of general (batch) after-fabrication hot-dip galvanizing and prefabricated, continuous galvanized sheet.

Hot-Dip Galvanized Rebar vs. Epoxy-Coated Rebar

This comprehensive handout compares hot-dip galvanized rebar with epoxy-coated rebar including a side-by-side comparison of performance, a detailed account of concrete corrosion, and galvanized rebar bridge case studies.

Hot-Dip Galvanized Steel vs. Paint

This handout is a detailed cost comparison of hot-dip galvanizing and paint. The handout features a side-by-side comparison of weather dependency, bond strength, service life, and much more. It also compares the initial cost and maintenance cost of hot-dip galvanizing with 4 paint systems.

Hot-Dip Galvanized Steel vs. Weathering Steel

This one-page handout provides a side-by-side comparison of hot-dip galvanized steel and weathering steel. The analysis includes fatigue life, inspection, appearance, corrosion rate, and much more. In addition, the handout explains the performance of both steels in five different environmental conditions.

Hot-Dip Galvanized Steel vs. Zinc Spray Metallizing

This one page handout is a detailed comparison of hot-dip galvanizing and zinc spray metallizing. The publications features a side-by-side analysis of weather dependency, bond strength, service life, and much more.

Hot-Dip Galvanized Steel vs. Zinc-Rich Paint

This handout is a detailed comparison of hot-dip galvanizing and zinc-rich paint. The handout features a side-by-side analysis of weather dependency, bond strength, service life, initial/maintenance costs, and much more.

Hot-Dip Galvanized Steel vs. Mechanical Plating

This one-page handout is a comprehensive side-by-side comparison of general (batch) after-fabrication hot-dip galvanizing and mechanical plating.