Our latest product development on our TetraWal range of retaining wall galvanized steel posts, joiner systems and cleats involves a redesign to increase the surface area that is hot dip galvanized, thereby increasing the corrosion protection and service life of a broader range of TetraWal components.
We have previously compared retaining wall products that have been “Batch Galvanized” as is the TetraWal range, to “Continuously Galvanized Sheet” posts which are thinner in all aspects. Highlighting the impact of downgraded welding practices on the latter, that reduce zinc thicknesses on theses posts, thereby reducing the corrosion protection of the steel and the years of serviceable life for HDG steel components. Now we’re taking TetraWal’s high quality products one step further and redesigning any TetraWal components that have previously featured plate-on-plate elements.
Plate-on-plate elements are fabricated prior to galvanizing and inhibit the ability of molten zinc to penetrate the joins and flow between the two surfaces to consistently cover all faces of the steel. As a result, internal surfaces are not galvanized to a consistent thickness and may not be galvanized at all. Although the zinc coating is cathodic and protects the steel from corrosion, those internal surfaces will bleed rust over time as the uncoated steel slowly corrodes.
Our redesign adapts fabrication to create a gap between plates of at least 2mm. This allows our pre-treatment process to adequately clean the steel between the plates, ensures appropriate venting and hot dip galvanizes the inner surfaces effectively, without compromising weld strength along the joins. This redesign ensures all facings of TetraWal retaining wall steel joiner posts are 100% galvanized to AS/NZS4680. This delivers a longer service life for TetraWal fence cleats and 90 degree corner sections, equivalent to that of the solid, single steel component C-sections and H-sections within our range.