Performance Metals supplies both traditional zinc and premium high performance Navalloy anodes for use in fresh, brackish and salt water. Navalloy anodes are environmentally safe, heavy metal zincs poison the environment. Anodes are available in full kits and individual anodes for your sterndrive, shaft and hull anodes. Performance Metal leads the industry with the patented "Red Dot" wear indicator to help insure timely anode replacement.
Sacrificial Zincs or Anodes are used anytime you have different metals that are physically or electrically connected and immersed in water. These submerged metals will cause some amount of electrical current to flow between them. The electrons that make up that current flow are supplied by the loss of one of the metals. Metal is lost in the form of metal ions - directly into the water! Temperature and salinity (how salty the water is) also factor into how rapidly the metal is corroded. This is called galvanic or dissimilar metal corrosion and if left unchecked, it can quickly destroy underwater metals.
Common metals subject to galvanic corrosion are bronze or aluminum propellers on a stainless steel shaft; but rudders, rudder fittings, metal struts, outboards, stern drives as well as heat exchangers and through-hull fititngs are also at risk. The way to counteract galvanic corrosion is to add a third metal into the circuit, one that gives up its electrons easier than the metals you want to preserve. This piece of metal is called a sacrificial anode, and most often it is zinc. In fact, most boaters refer to sacrificial anodes simply as zincs.