While liquid paint is still the most widely implemented architectural finish in Australia, there is another that has enjoyed steady progression in popularity since its introduction in the late 1950s.
There are a number of factors leading to the increasing uptake of powder coating for architectural elements, but this can be mostly attributed to the growing awareness within the industry of the performance and cost benefits it can offer projects, given the right circumstances.
Below are the four key differences between powder coating and liquid paint.
Generally speaking, thinning agents or solvents are used to “thin” liquid paint prior to application. This process provides a consistent and even finish. However, wet paints can take a long time to fully cure due to curing additives and the use of solvents. The curing time for wet paints is also largely dependent on atmospheric conditions, reducing drying time consistency from one project to the next, particularly with external elements.
Comparatively, powder coating is a dry paint system. The coating is applied as a dry powder and then chemically fused to a component at high temperatures: a process known as curing. When coated components are cooled following the curing process, they are ready to be packed and shipped.
Powder coating is applied electrostatically to components. In doing so, powder that has not adhered to the component, known as overspray, can be reclaimed and reused. This makes powder coating a cost effective and environmentally friendly coating solution.
The preparation, application and curing processes for powder coating are carried out in a controlled factory environment and in a shorter time frame compared to wet paint. However, not all products can be powder coated. The decision of whether powder coating or liquid paint is more suitable is dependent on the size, weight and even location of components.
Expenses can be reduced in several areas by using powder coatings. For example, the application process is easier to automate, reducing labour costs. Operational costs are also minimised through the lack of waste produced by powder coating.
No Volatile Organic Compounds (VOCs).
Additionally, while traditional liquid paint and protective coating systems are based on solvents that contain VOCs, powder coating is a “dry” finish. This means that powder coatings contain no solvents and release a negligible amount of VOCs, offering up environmental benefits additional to minimising waste.
Powder coatings can offer a higher level of durability to external stressors such as UV degradation and environmental chemical exposure. This is particularly relevant for components such as windows and door framing, exterior cladding, fences, and balustrades, which are in constant use and exposed to harsh environments.
According to Gareth Connell, Regional Specification Manager at AkzoNobel, while there are pros and cons for both coating systems, the key is to use the right combination of both powder coating and liquid paints on a project. With the right combination, the project can enjoy the long-term performance benefits of powder coatings and reduced maintenance costs, such as onsite refurbishing or component replacement.
Powder coated architectural elements can have exterior performance life expectancies of up to 50 years with minimal care and maintenance. This makes powder coating an economic choice in reducing long-term asset management costs.