Galvanic Corrosion

Brass on Weathering Steel

Corroding Weathering Steel

The early rust forms in discrete crystallites that are fine, red and diffusely reflecting, like hematite. The massive recrystallized layer is a shiny blue, approaching the blue-black of specular hematite. Thus portions of weathering steel that have seen different amounts of wetting and drying will have different degrees of recrystallized oxide and will have different appearances. Most weathering steel sculptures in most environments provide surfaces that see varied amounts of wetting and drying. Runoff water tends to produce long-lasting streaks or other patterns of redder oxide on lower portions. Similarly, in wetter climates the overall color of weathering steel structures will have generally have an overall redder cast relative to those exposed in drier climates.