What is the electromotive force series?
The electromotive force series, EMF for short, is a listing of metals indicating their relative electrical potential to corrode. The closer the metal is to the top or active end of the EMF the more likely it is to corrode. The closer the metal is to the bottom or passive end of the EMF the less likely it is to corrode. • Why is aluminum used so much if it is so active on the EMF series? Because of the inherent property of aluminum to create a tightly adhering oxide layer on the surface, it becomes very passive and therefore is less likely to corrosive. It will corrode very quickly should the oxide coating become damage. • What is the green stuff on the outside of copper gutters and is it good for corrosion prevention? That green stuff on the outside of copper is what we call patina. It is not a tightly adhering oxide film such as the film on aluminum, but rather an electrically resistant coating. The patina slows corrosion because it resists the electron flow in a corrosion cell. • Whe
