Curing of powdercoat completed

Nu-Wall cladding is supplied to a project pre-finished to the specifications required by the customer or the designer. Some specifications call for anodising, which retains the metallic appearance of the aluminium, either in natural silver or with a bronze colouring. The majority of specifications we see, however, call for finishing with a powdercoat colour.

Powdercoating involves the application to the aluminium of the colour in a powder form – this is done electrostatically; the powder being attracted to the metal by an electrical charge. At this stage in the process, the appearance of the powder is almost like velvet as it has yet to be cured. The curing takes place in an oven at a temperature of around 180 – 200 degrees C, and it is this stage that turns the powder into the hard, durable finish with an appearance similar to sprayed paint.

Powdercoat colours are available from several manufacturers in New Zealand; each having a wide range of stock colours for which colour charts and swatches are available on request. Due to the different manufacturing processes involved, the range of “stock” powdercoat colours offered is nowhere near as extensive as with paints; however it is a fact that small batches of powder are able to be made to order, allowing the specifier to basically choose any colour they want. We do find, however, that in the vast majority of cases a satisfactory choice is able to be made from the manufacturers’ colour charts.

The durability of powdercoat finishes is extremely high – the Nu-Wall cladding will retain its appearance year after year with the only maintenance requirement being washing with water containing mild detergent. The adhesion of the cured powder to the aluminium is very strong and has great resistance to chipping. For applications located in environmentally harsh locations; e.g. coastal marine, manufacturers offer extra-durable formulations of their powdercoat products which are warranted to meet such performance requirements.

Damage can occur to powdercoat finishes – while they are much more durable than a normal paint finish, accidents sometimes happen, necessitating some localised remedial work. For such occurences touch-up products are available which have been colour-matched to the powdercoat manufacturers’ ranges. These are available on short lead-times, in either dab-stick or aerosol spray forms.