"Powder coating" refers to a process, not a single product. Behind the colour there is a resin, and the resin decides whether the finish will stand up to sun, chemicals or impacts. Here are the main families, as described by manufacturers and the trade press.
Epoxy: protection, but indoors
Epoxy offers excellent resistance to corrosion and chemicals, and a very hard film. Its weak point is the sun: exposed to ultraviolet rays, it chalks, meaning it turns dull and powdery on the surface. Products Finishing lists electrical components, automotive parts and rebar among its typical uses. It is therefore kept for parts that do not see the sun, and it is often used as a primer.
Polyester: the outdoor choice
Polyester resists the weather and keeps its colour. It is the most common family for anything that goes outdoors: wheels, furniture, railings, extrusions. There are two types, depending on the curing agent, with or without TGIC; Powder Coated Tough details the differences. The superdurable versions hold up longer in the sun.
Hybrid, polyurethane and fluoropolymer
Hybrid blends epoxy and polyester. It applies easily into recesses but, like epoxy, it does not do well in the sun: you find it on shelving, office furniture and appliances. Polyurethane gives a thin, smooth film that resists the weather well. Fluoropolymer offers the best ultraviolet resistance, at a higher price, as this overview from ChemQuest sums up.
How we choose
Three questions are almost always enough: will the part go outdoors, what will it come into contact with (salt, fuel, cleaning products) and what look do you want? We work with the catalogues of Prismatic Powders, Prism Powder Coatings and Protech. Describe how the part will be used in your quote request and we will suggest the right powder.
In summary
- Epoxy: very resistant to corrosion and chemicals, but it chalks in the sun.
- Polyester: the outdoor family; superdurable for long exposure.
- Hybrid: practical indoors. Fluoropolymer: the best ultraviolet resistance.
- The use of the part decides the powder, not just the colour.
