Zincs Aren’t Zinc?
Posted: August 1, 2013 | Tag: Corrosion/Zincs
I thought zincs were made of zinc, but I’ve noted some zincs seem to be made of aluminum. What’s with that?
What is commonly referred to as a “zinc” is really a sacrificial anode generally bolted or welded to underwater marine gear to protect that gear against galvanic corrosion, caused by two dissimilar metals being connected in water. The anode is corroded (sacrificed) rather than the gear. Traditional anodes, made primarily of zinc, contain small amounts of cadmium, and elevated cadmium levels have been found to be toxic to marine life. This has led to the development of sacrificial anodes made primarily of aluminum, and their manufacturers say they work better in salty or brackish water than traditional zincs.