< ANODISING
HOT DIP GALVANISING, CADMIUM COATING, STOVE ENAMELLING, POWDER COATING
Galvanising, stove enamelling and other similar coatings can be applied to sculptural and other design elements, either as a corrosion resistant barriers, or as decorative finishes in their own right. A typical example of a protective coating application would be the ZINC GALVANISING of a steel sub-frame for supporting a sculpture.
A workpiece for zinc galvanising is degreased, then hung from a gantry, before dipping in a bath of molten zinc (melting point 419.6°C). Designs created from hollow sectioned tubes are normally galvanised both internally and externally to provide maximum protection and service life. To enable a galvanised coating to be applied to the inside of a blanked off hollow section, a series of drilled drain apertures (of at least 3/4 inch [15-20 mm] diameter) are put through the tube’s walls. Access holes enable fluid zinc to enter, coat, and then drain from the interior of the design. Excess zinc and air can escape the interior of hollow sections through these relief holes, trapped air could distort the metalwork, or cause a closed off section to rupture.
Stove enamelling provides hard and durable protective coating to metals by depositing a layer of ALKYD RESIN (phenolformaldehyde resin for example). The resin deposit can be applied to the design by simply DIPPING (cheapest method), or else by dipping and ELECTROSTATIC DE-TEARING – a process which draws off any excess coating to provide a quality finish. Whilst some stove products can be simply air dried, most are baked in a convection oven for anything up to an hour at 445-480°F (230-250°C).
METAL SPRAYING & BRONZING >
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