Dross

In hot-dip galvanizing, dross is a specific metallurgical waste product formed by the reaction between molten zinc and iron. It is not just "dirt"; it is a zinc-iron intermetallic alloy.

• Bottom Dross: Hard, sandy crystals that sink to the bottom of the kettle. If disturbed, they stick to the pipe, creating rough, pimple-like defects.

• Top Dross: Oxide-rich skimmings that float on the surface.

   

• Why it matters: Effective dross removal is critical for maintaining a smooth, shiny coating and preventing zinc waste.