Answer
Apr 18, 2023 - 05:19 PM
Impurities in the cooling water
Impurities in the cooling water, such as salts, minerals, and organic matter, can increase its electrical conductivity enabling electrolysis. These impurities can come from a variety of sources, such as saltwater / seawater or sometimes even freshwater sources.
Poorly operating cathodic protection systems
Cathodic protection systems are used to protect metal components on a boat from corrosion by providing a more easily corroded "sacrificial" metal that corrodes first. However, if the cathodic protection system is not properly installed or maintained, it can cause electrolysis and corrode the heat exchanger.
Dissimilar metals: A galvanic reaction is another kind of electrolysis. If different types of metals are used in the heat exchanger, such as copper and aluminum, they can create a galvanic cell when they come into contact with the cooling water. We find that in the marine industry that this is often accompanied by a small leak in salt water. The salt water then bridges the two metals and creates a path through which the corrosion can feed between the salt and stray currents.
This cell generates an electric current, which causes metal ions to dissolve into the surrounding water source (deplate) and corrode the heat exchanger (remove metal from the heat exchanger and flow those small molecules into the surrounding water source). Although technically this is electrolysis, it’s more commonly recognized as corrosion by the user. It is common when there is a brass header and an aluminum body. As soon as a salt bridge is built across the two components they will become one and corrode each other.
©2023 Mr. Cool Marine LLC
Impurities in the cooling water, such as salts, minerals, and organic matter, can increase its electrical conductivity enabling electrolysis. These impurities can come from a variety of sources, such as saltwater / seawater or sometimes even freshwater sources.
Poorly operating cathodic protection systems
Cathodic protection systems are used to protect metal components on a boat from corrosion by providing a more easily corroded "sacrificial" metal that corrodes first. However, if the cathodic protection system is not properly installed or maintained, it can cause electrolysis and corrode the heat exchanger.
Dissimilar metals: A galvanic reaction is another kind of electrolysis. If different types of metals are used in the heat exchanger, such as copper and aluminum, they can create a galvanic cell when they come into contact with the cooling water. We find that in the marine industry that this is often accompanied by a small leak in salt water. The salt water then bridges the two metals and creates a path through which the corrosion can feed between the salt and stray currents.
This cell generates an electric current, which causes metal ions to dissolve into the surrounding water source (deplate) and corrode the heat exchanger (remove metal from the heat exchanger and flow those small molecules into the surrounding water source). Although technically this is electrolysis, it’s more commonly recognized as corrosion by the user. It is common when there is a brass header and an aluminum body. As soon as a salt bridge is built across the two components they will become one and corrode each other.
©2023 Mr. Cool Marine LLC
