Water heaters with well-maintained and regularly replaced anode rods can last far longer than their typical life of eight to twelve years. With millions of water heaters ending up in a dump every year, the need to prolong their life is vital. Defects in water tanks caused during manufacturing, transportation, or installation will rust and shorten the tank’s life.
A zinc anode rod in Canada protects steel and glass-lined water heaters from this corrosion. The zinc in the anode rods prevents this rust in metal surfaces by attracting the corrosion to itself, ‘sacrificing’ itself. The metal of the sacrificial anode then absorbs the corrosion instead of the protected metal. This process is known as cathodic protection.
The Science Behind Cathodic Protection
Four essential elements must be present for corrosion to occur:
- A host site from which current flows
- A medium capable of conducting current, such as water
- A destination site where no current flows
- A metal path between the destination and host sites
When more than one metal is immersed in liquid, the one with the highest negative electrochemical capacity will rust first. In this process, ions on the surface of metal are transferred to a less active substance. A metal anode acts as this sacrificial substance. To provide protection for your water heater, manufacturers typically use aluminum anode rods, zinc anode rods, or a combination of aluminum and zinc anode rods.
Constantly releasing ions into the water, the sacrificial anode will degrade, limiting its capabilities. As it degrades, its protective qualities decrease, leading the water tank to corrode. The sacrificial anode component should be regularly maintained and replaced if needed to extend the lifespan of your water heater significantly.
Knowing when a zinc anode rod in Canada needs to be replaced requires frequent monitoring. Manufacturers of water tanks often recommend that you check the anode’s condition every one to three years. If it is worn out beyond half of its original state, you should replace it. This task can be done by the homeowner or a professional. An annual draining of your water heater to reduce sediment build-up in the tank is also a good idea.
Other Types of Anodes
Marine anodes are commonly used in the protection of military, private, and commercial structures and vessels from corrosion in a marine environment. Like the anode rods used in residential and commercial water heaters, marine anodes’ sacrificial nature prolongs the life of ships, boats, and marine structures.
Marine zinc anodes are the optimal choice for saltwater applications’ protection in industries such as commercial marine, oil and gas, and defence, as they are less resistant to saltwater’s electrolytes. The zinc prevents rust from forming in other metal surfaces as it attracts the corrosion to itself, dissolving over time. This process protects hulls and other metal parts from damage and prolongs their lives.
Some of the many other applications for marine zinc anodes include:
- Sea Tanks
- Bottom Plates
- Shaft Tunnels
- Ballast Tanks
- Cargo Tanks
- Steel Pipelines
- Production Platforms
- Steel Pier Piles
- Heat Exchangers
Visit the Canada Metal website to view their wide selection of anode rods, including zinc anode rods in Canada, marine anodes, and many others.