How to choose between hot-dip galvanising and paint for exterior steel.
Hot-dip galvanising and painting are the two common ways to protect steel outdoors. They cost differently, last differently, and suit different situations.
The steel is dipped in molten zinc, which bonds to the surface and forms a coating that also covers internal corners and edges. It requires no further finishing and typically lasts decades without maintenance.
Paint or powder coating forms a film on the surface. It is available in any colour and looks smooth, but it only covers the outside, needs surface preparation, and must be re-coated over time.
Galvanising suits exterior steel, parts in contact with moisture or soil, and agricultural or mining environments where maintenance is difficult. It protects edges and internal surfaces that paint cannot reach.
Paint suits interior work, parts where a specific colour must match, and light sheet that cannot withstand the heat of the galvanising bath. It also allows a smoother cosmetic finish.
Galvanising usually costs more up front but lasts far longer with no maintenance. Paint is cheaper initially but needs re-coating, so it can cost more over the life of the part.