What is Powder Coating?
Powder Coating is a dry form of paint which is a popular way of painting metals, such as aluminium. This dry finishing process is used for providing a high-quality and durable finish, in which there is a range of colours and textures available.
How is it Made?
Most powder paints start life as a liquid, which is very similar to spray paint. From here, the resin from the paint, pigments and various other components are mixed into a homogeneous mass. Through melt mixing, cooling and grounding, the powder is formed. Colour matches are difficult to achieve due to the process in which powder coatings are made. Once the pigments have been added to the mixture in the beginning phase, there is no way to change this later on, compared to paint that can have additives added.
How is it done?
Powder coating is mainly applied to a metal surface using a spray gun, in which is applies an electrostatic charge to the powder. This way, the powder will be attracted to the metal due to the charge. Then, the spray will be baked, where it melts, flows and cures. Being applied this way does not affect the quality of the workmanship or material, instead, it increases the durability of the application to ensure a high-quality finish.
Orange peel is a surface condition that looks just like its name – the bumpy skin of an orange. This is typical of some powders, which will continue to deteriorate as the thickness of the film becomes excessive.
Most powders will apply at a range of 1.5-2.5 mils, which is thousandths of an inch in “coater language”, however when you start to build heavier than this, the orange peel will form and can become a definite problem.
Polishing out Defects and Scratches?
Even though powder coated surfaces are more resistant to scratches, chippings and colour fading, there can still be some defects through time. However, many small imperfections, minor orange peel, and some scratches can be polished out.
Is Powder Coating environmentally friendly?
Unlike liquid paint, there are no solvents used in powder coating, thus they produce very low gas emissions when curing. There is only a slight amount of Volatile Organic Compound (VOC) in most powders, rating at less than 1 pounds per gallon, whereas liquid paints range between 2.5-7 pounds per gallon.
Furthermore, there is very little waste of powder, as over-spray can be collected and re-used, rather than just thrown away like with paint over-spray.