In the hot-dip galvanizing process, steel is completely coated with corrosion-inhibiting zinc, which forms a highly abrasion-resistant metallurgical bond with the base steel. In order to ensure that all interior and exterior surfaces are protected from corrosion, entire steel fabrications are lowered into and raised out of cleaning solutions, flux solutions, and molten zinc metal.
The use of hoists and cranes is standard in galvanizing facilities. To ensure proper handling, lifting points should be incorporated into the fabrications design. Lifting points provided only for hot-dip galvanizing purposes may be removed after galvanizing.
Large assemblies are usually supported by chain slings or lifting fixtures. Special jigs and racks can be used to simultaneously galvanize large numbers of similar items. Perforated baskets are used to galvanize smaller articles such as nuts and bolts.
Chain, wire and other holding devices used to support materials being galvanized can leave markings on the galvanized item, unless special lifting supports or holes are provided. These markings are usually completely galvanized; if not, they can be touched up, for aesthetic reasons, if desired. If temporary lifting points are removed after galvanizing, exposed areas may similarly be touched up.
The weight of the fabrication also should be considered in the design of products to be hot-dip galvanized because of the handling required to move items throughout the galvanizing facility. Contact your galvanizer to discuss weight-handling capacity if extremely heavy items are to be galvanized.
With respect to providing lifting points, consider the following:
- Where possible, lifting points (see ilustration below) should be provided at the quarter points for symmetrical parts; this avoids chain- or wire-marks on the sides of the parts
- Holes may be included in the design to allow the galvanizer to hang materials from overhead fixtures