Zinc anodes can extend the useful life of metal parts
Anyone who has spent time near beaches knows that metal items exposed to saltwater begin to rust quickly. Freshwater encourages oxidation, as well, but because saltwater is a good conductor, electrons move easily through it, accelerating the reactions that cause corrosion.
Cathodic protection is one solution to controlling corrosion on metal surfaces that come into frequent contact with saltwater. It works by connecting metals with different corrosion potential to a sacrificial metal, also referred to as an anode, which attracts the corrosion and protects the other materials from damage.
Anodes must be less resistant to corrosion than the metals they are protecting, and are often made of Zinc, Aluminum or Magnesium. All three of these materials work cathodically in their pure state, and they can be alloyed with various other metals to make them more efficient. Zinc anodes are used to protect steel water or fuel pipelines; storage tanks, such as water heaters; steel pier piles; boat, ships and submarines; and items like condensers and heat exchangers.
On boats, zinc anodes can be placed on hulls, propeller shafts, rudders, trim tabs, outboard engines, stern drives, and in the cooling system of most inboard engines to protect metal parts from galvanic corrosion. Galvanic corrosion occurs because boats often use dissimilar metals for parts, such as an aluminum stern drive and a bronze through-hull. When those materials are placed in seawater, currents travel from the more noble bronze to the less noble aluminum, and, as a result, the aluminum begins to deteriorate. Connecting these two materials to a Zinc anode increases current activity, but because Zinc is the least noble material of the three, corrosion damage will be primarily confined to the Zinc, thereby extending the useful life of the Aluminum and Bronze components.
Brooklyn, New York-based Belmont Metals is experienced in the manufacture of sacrificial anodes and has established anode alloys with consistent, known output throughout their service life. Zinc anodes are available in a large assortment of sizes and shapes, and Belmont Metals offers Types ZHS; ZHC; ZSS; ZEP (Style A, B and C); ZTS, and ZRN. The company also offers custom formulas, shapes, sizes and straps. All of the company’s Zinc anodes are available for industrial purposes and come with full certification for government use.
Types ZSS, ZHS/ZHB/ZHST, and ZHC are often used in marine applications. Type ZSS is a rectangular slab with a galvanized steel strap core and can be mounted on a ship’s hull. ZHS/ZHB/ZST are offered in either rectangular slab or tapered anodes and are attached to either boats or ships through a galvanized steel strap core, a brass strap core or a phosphor bronze strap core. Both the Type ZSS and ZHS/ZHB/ZST anodes are available with mounting holes in the strap cores. Type ZHC is a rectangular slab that can be mounted on boat, ship or submarine hulls by using two lugs and attaching it through the anode’s galvanized steel strap core.
Zinc anodes are inexpensive, predictable, dependable and compatible with all marine seawater needs. The corrosion resistance results provided by proper application of Zinc anodes will save time and money in the long run.