Powder Coating
Powder coating sprays a dry polymer powder onto a part electrostatically and then bakes it at around 160–200 °C to form a tough, even finish, typically 60–120 µm thick. It gives durable, colourful protection to steel and aluminium fabrications, enclosures and brackets.
What it is
Charged powder particles are attracted to the grounded part and cling to it. In the curing oven, the powder melts, flows and cross-links into a continuous coating with no solvents, which is why powder coating has very low emissions and little waste.
Good pre-treatment, such as phosphating or zirconium conversion for steel and chromate-free conversion for aluminium, is essential for adhesion and corrosion resistance. Epoxy powders are for indoor use, polyester for outdoor UV resistance, and hybrids for general use.
Typical applications
- Electrical panels, enclosures and cabinets
- Sheet metal fabrications, frames and brackets
- Machine guards and covers
- Furniture, racks and shelving
- Aluminium profiles and outdoor structures
Suitable materials
- Mild steel (with phosphate or zirconium pre-treatment)
- Galvanised steel (with suitable pre-treatment)
- Aluminium
- Stainless steel (for colour)
Points to consider
- Specify the RAL colour, gloss level and texture; ask for a sample panel if colour is critical.
- Threads, holes and electrical earth points should be masked or plugged.
- Parts must withstand the curing temperature; assemblies with rubber, plastic or electronics cannot be coated whole.
- Sharp edges get thinner coating; rounded edges improve corrosion resistance.
- Choose polyester or super-durable polyester for outdoor UV exposure; epoxy chalks in sunlight.
Frequently asked questions
Is powder coating better than paint?
For most metal parts, yes. It is thicker, tougher and more chip-resistant than conventional wet paint, and uses no solvents.
How thick is powder coating?
Typically 60–120 µm. Thicker coats are possible for extra protection, but may affect fits and threads.
Can galvanised steel be powder coated?
Yes, with the right pre-treatment and sometimes a pre-bake to avoid outgassing pinholes. The combination (duplex system) gives very long corrosion life.