Technical Articles
Technical content published for the HDG community — written for practitioners, by practitioners.
Coating Thickness: How to Specify, Measure and Verify It
ASTM A123 and ISO 1461 can reach opposite verdicts on the same beam. How each standard samples, reads and judges thickness, which test settles a dispute, why neither sets a maximum, and a specification clause that answers ten questions before the steel is dipped.
Read the article → Design for GalvanizingVent and Drain Holes for Hot-Dip Galvanizing: How to Size and Place Them
Three published rulebooks size the same hole three different ways, and the gap between them is roughly a factor of three in open area. What each rule requires, sizing tables for CHS, SHS and RHS, the placement errors that cause most rejections, and the clause to put on the drawing.
Read the article → StandardsASTM A123 & ISO 1461 — New Editions: What Changed
Both standards were revised, ASTM in 2024 and ISO in 2022. Renovation rules tightened, ultra-low-reactivity steels finally got a rule, and material categories became the thing that actually moves your zinc. Corrected 2026-08-18: the coating grade for structural shapes did not change.
Read the article → Compare & DecideCorrosion Protection for Steel: Every Method Compared to Hot-Dip Galvanizing
Paint, zinc-rich paint, electroplating, mechanical plating, sherardizing, thermal spray metallizing, hot-dip aluminizing, duplex, weathering steel, stainless and cathodic protection — mechanism, standard, service life and cost, and when each one beats HDG instead of losing to it.
Read the article → Plant OperationsZinc Consumption KPIs: How to Measure Plant Efficiency
Revision 2.0, revised after technical review. Industry figures as a ceiling, an expert's field range as the aim point, and 30,510 tonnes of my own 2025 production as a case study, with the ash number that does not flatter me.
Read the article → Bath ChemistryThe Kleingarn Curve in HDG Pickling Bath Management
In an HCl pickling bath, pickling speed is set by the balance between free acid and dissolved iron — not by acid alone. How the Kleingarn relationship lets you read it and plan bath life.
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