Corrosion vs. Electrolysis
How to protect your investment
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CORROSION
Corrosion is the process of degrading or weakening of a metal by something that reacts with the metal. Corrosion can occur from exposure to air in the form of rust. However, when the metal is introduced to water it speeds up this reaction. Also, if minerals in the water such as salt, calcium, etc. are present, the speed of the process increases again.
To protect against corrosion, all exposed metal on any Kasco Floating Fountain, Pond Aerator, or Water Circulator is stainless steel (a metal the resists corrosion well) except for the Sacrificial Zinc Anode (except for the 1400JF). Metals are ranked on a Noble Scale as to how well they resist corrosion. If two types of metals are present (Stainless Steel & Zinc), the metal that resists corrosion the least (Zinc) will deteriorate before the metal that resists corrosion the best (Stainless Steel). Therefore, the Sacrificial Zinc Anode standard on all Kasco units (except the 1400JF) is designed to protect the unit from corrosion because the Zinc will deteriorate before the Stainless Steel.
The Sacrificial Zinc Anode creates a sphere of protection around the unit. It is installed on the motor shaft because the spinning motion assists in the protection quality of the Zinc. As the Zinc deteriorates through the corrosion process, the sphere of protection decreases. If the Zinc deteriorates enough, eventually the sphere will be too small to protect the entire motor unit and damage could occur to the motor unit. That is why it is crucial to inspect your unit and Sacrificial Zinc Anode routinely, and if the Sacrificial Zinc Anode is corroded or deteriorated to half of its original size or less, it should be replaced. The more minerals, such as salt content, the quicker the corrosion will occur, therefore, the Sacrificial Zinc Anode must be checked more often. In areas of high mineral content, it is suggested to check the Anode every couple months.
ELECTROLYSIS
Electrolysis is similar to corrosion, in the fact that it is the process of deteriorating metal by a reaction process. Although the results are the same, corrosion and electrolysis differ by the time required for the process and what usually causes the process.
Electrolysis is a reaction between metal and electrical energy. Electrolysis occurs when electrical current is "leaking" into the water and can come from a variety of things such as improperly grounded electrical devices and power circuits, old electrical devices in contact with the water, batteries in boats, etc. Also, since this process includes a stronger reaction agent (electricity), the process is much quicker than corrosion.
The Sacrificial Zinc Anode does offer some protection against electrolysis. However, a Sacrificial Zinc Anode can be completely deteriorated and damage to the unit can occur in as little as a couple weeks or less. This is largely dependant on the amount of electrical current in the water and how well the current travels through the water. Electricity uses particles in the water to travel, not the water itself, so the more minerals, such as salt, the further and quicker electricity can travel through the water to attack the unit.
There are basically two options to protect your equipment from electrolysis. One is to keep replacing the Sacrificial Zinc Anode as often as needed. Two is to find the source of the stray voltage and eliminate it. Option two is a much more effective and reliable option than option one since damage can occur before an Anode can be changed and it becomes costly to continually change the Anode.
It is recommended to contact a qualified electrician to help you determine what and where the stray voltage is coming from. This may feel like finding a needle in a hay stack, but can and should be done to eliminate the problem. Some common examples we at Kasco have seen are improperly wired/grounded outlets, boats with electrical equipment, boat lift, old buried power cables near the shoreline, and other electrical equipment in the water. Below is an example that is extreme, but illustrates the problem of electrolysis.
Example: A Kasco customer on the East coast had several Kasco De-Icers in a harbor to prevent ice formation around docks and boats. The De-Icers would become corroded very quickly (within months) and holes would occur in the Stainless Steel motor housing about 5" from the bottom of the unit. It was the same problem with each De-Icer. It was determined that electrolysis was causing the problem since it was happening so quickly and to each unit.
The Kasco customer hired an electrician to help determine what was causing the problem. After an intensive and thorough search of the entire area, the electrician was led to an old, wooden boat several hundred yards away from the De-Icers. Inside this old, wooden boat was an old pump with a non-polarized plug that was plugged into a ungrounded outlet. Since the pump was not sufficiently grounded, voltage was allowed to leak through bolts in the wooden hull of the boat. Since this was an application in salt water, the electricity was able to travel enough distance to deteriorate the De-Icers several hundred yards away. The owner of the boat was notified and the pump and outlet were grounded correctly and the problem did not occur again.
Our compliments go out to this electrician who found the problem and for taking care of the problem.
Corrosion and Electrolysis can cause great damage to metals in a marine environment. The Sacrificial Zinc Anode will help protect your Kasco Floating Fountain, Pond Aerator, or Water Circulator. However, it is impossible to protect against all forms of electrolysis and if the Anode is not inspected regularly, your protection will also be compromised.