Hybrid Zinc Coatings: Specifying HDG + TSZ

Hot-dip galvanizing (HDG) and thermal spray zinc (TSZ) are two proven zinc coating corrosion protection systems, each offering unique advantages depending on project requirements. This guide provides a practical framework for specifying HDG, TSZ, or a combination of both, helping designers, engineers, and owners select the most effective and economical all-zinc solution. It explains how differences in application method, coating characteristics, size limitations, accessibility, durability, slip factor, and lifecycle cost can influence coating selection across a wide range of structural and industrial steel applications.

In addition to outlining the strengths and limitations of each coating system, the publication explores when a hybrid HDG + TSZ approach can deliver the greatest value—particularly on projects that include oversized components or complex geometries. Real-world case studies demonstrate how combining HDG and TSZ has been successfully used on bridges, infrastructure, and offshore structures to balance cost, performance, constructability, and long-term corrosion protection. The guide also addresses compatibility considerations, repair options, appearance, and weathering, making it a comprehensive resource for specifying zinc coatings with confidence.

The 14 page guide was published in 2026 and contains a hybrid zinc coating selection flowchart and worksheet to help specifiers easily evaluate whether steel articles are ideal for HDG, TSZ or a combination of both. The Hybrid Zinc Coatings Worksheet & Flowchart can be downloaded as a two-page fillable PDF form to assist with making this decision.