Answer
May 31, 2023 - 04:10 AM
Electrolysis is a phenomenon that occurs in boats and other metal structures that are exposed to water. It is the process by which electric current flows through a conductive medium and causes metal ions to dissolve, resulting in corrosion and damage to the metal structure. Galvanic reactions are also technically electrolysis but discussed separately in this document.
Electrolysis is the process of deplating a high density condition (in this case a heat exchanger) to a lower density condition (the surrounding water source) as the charge in the water causes the copper molecules of the heat exchanger to release and move into the solution that we refer to as raw water or seawater.
Stray electrical currents can be generated by a number of sources on a boat, such as improperly grounded electrical systems or damaged wiring. If these currents flow through the cooling water, they can cause electrolysis and corrode the heat exchanger. A well grounded boat can keep the electrolysis at bay when tied to the earth usually at the charging station. Someone leaving their charging lines in the water (particularly if they have cracked plastic coatings) is the primary example of how the water is charged. This begins the process of electrolysis on a boat.
Electrolysis is a chemical process that occurs when an electric current flows through a conductive medium and causes a chemical reaction to occur. In the case of boats, electrolysis occurs when the metal parts of the boat are exposed to water that contains electrically conductive materials, such as dissolved salts and minerals. It is most aggressive when there is an electrical charge in the water.
It can happen either internally (invisible to the user) causing a leak, most commonly at the tube bundle header; but, also shows itself by creating holes in the bundle tubes.
It can show itself externally which looks like common corrosion. This is the fault of your grounding system and is not influenced by the construction of the heat exchanger.
When these conductive materials (electrolytes or salty water) come into contact with the metal parts of the boat, they create a conductive pathway that allows electric current to flow. This current causes metal ions to dissolve, resulting in what appears to be corrosion and damage to the metal parts of the boat. It is actually depleting of the metal in the water which detaches it from the coatings and (in most cases) the heat exchanger looks corroded. The chemical reaction that occurs during electrolysis can be summarized as follows:
At the anode (positive electrode): The metal at the anode dissolves and becomes ionized, releasing electrons into the solution. For example, if the anode is made of zinc, the following reaction will occur:
Zn → Zn2+ + 2e-
At the cathode (negative electrode): Electrons from the anode combine with positive ions in the solution, causing the metal to plate out on the cathode. For example, if the cathode is made of copper, the following reaction will occur:
Cu2+ + 2e- → Cu
Overall reaction: The net result of this chemical reaction is the dissolution of metal at the anode (the heat exchanger has become the anode) and the deposition of metal on the cathode (which is the seawater). This process can result in the depletion of metal from the anode and the accumulation of metal on the cathode, which can cause corrosion and damage to the metal parts of the boat.
In a boat, electrolysis occurs when the metal parts of the boat (such as the engine, propeller, and other metal fittings) are exposed to water that contains electrically conductive materials. These materials can include dissolved salts and minerals, stray current from nearby boats or electrical sources, and other conductive materials that may be present in the water.
When these conductive materials come into contact with the metal parts of the boat, they create a conductive pathway that allows electric current to flow. This current causes metal ions to dissolve, resulting in corrosion and damage to the metal parts of the boat.
To prevent electrolysis from occurring, it is important to take several steps, such as using sacrificial anodes made of a more active metal, avoiding dissimilar metals, properly grounding the electrical system, and performing regular maintenance. These steps can help to minimize the occurrence of electric current and prevent the chemical reactions that cause electrolysis from taking place.
©2023 Mr. Cool Marine LLC
Electrolysis is the process of deplating a high density condition (in this case a heat exchanger) to a lower density condition (the surrounding water source) as the charge in the water causes the copper molecules of the heat exchanger to release and move into the solution that we refer to as raw water or seawater.
Stray electrical currents can be generated by a number of sources on a boat, such as improperly grounded electrical systems or damaged wiring. If these currents flow through the cooling water, they can cause electrolysis and corrode the heat exchanger. A well grounded boat can keep the electrolysis at bay when tied to the earth usually at the charging station. Someone leaving their charging lines in the water (particularly if they have cracked plastic coatings) is the primary example of how the water is charged. This begins the process of electrolysis on a boat.
Electrolysis is a chemical process that occurs when an electric current flows through a conductive medium and causes a chemical reaction to occur. In the case of boats, electrolysis occurs when the metal parts of the boat are exposed to water that contains electrically conductive materials, such as dissolved salts and minerals. It is most aggressive when there is an electrical charge in the water.
It can happen either internally (invisible to the user) causing a leak, most commonly at the tube bundle header; but, also shows itself by creating holes in the bundle tubes.
It can show itself externally which looks like common corrosion. This is the fault of your grounding system and is not influenced by the construction of the heat exchanger.
When these conductive materials (electrolytes or salty water) come into contact with the metal parts of the boat, they create a conductive pathway that allows electric current to flow. This current causes metal ions to dissolve, resulting in what appears to be corrosion and damage to the metal parts of the boat. It is actually depleting of the metal in the water which detaches it from the coatings and (in most cases) the heat exchanger looks corroded. The chemical reaction that occurs during electrolysis can be summarized as follows:
At the anode (positive electrode): The metal at the anode dissolves and becomes ionized, releasing electrons into the solution. For example, if the anode is made of zinc, the following reaction will occur:
Zn → Zn2+ + 2e-
At the cathode (negative electrode): Electrons from the anode combine with positive ions in the solution, causing the metal to plate out on the cathode. For example, if the cathode is made of copper, the following reaction will occur:
Cu2+ + 2e- → Cu
Overall reaction: The net result of this chemical reaction is the dissolution of metal at the anode (the heat exchanger has become the anode) and the deposition of metal on the cathode (which is the seawater). This process can result in the depletion of metal from the anode and the accumulation of metal on the cathode, which can cause corrosion and damage to the metal parts of the boat.
In a boat, electrolysis occurs when the metal parts of the boat (such as the engine, propeller, and other metal fittings) are exposed to water that contains electrically conductive materials. These materials can include dissolved salts and minerals, stray current from nearby boats or electrical sources, and other conductive materials that may be present in the water.
When these conductive materials come into contact with the metal parts of the boat, they create a conductive pathway that allows electric current to flow. This current causes metal ions to dissolve, resulting in corrosion and damage to the metal parts of the boat.
To prevent electrolysis from occurring, it is important to take several steps, such as using sacrificial anodes made of a more active metal, avoiding dissimilar metals, properly grounding the electrical system, and performing regular maintenance. These steps can help to minimize the occurrence of electric current and prevent the chemical reactions that cause electrolysis from taking place.
©2023 Mr. Cool Marine LLC
