Magnesium anodes are best used in applications where the anode can be easily replaced or the protection is only required for a short time period as in during construction or prior to impressed current cathodic protection being installed. There are three main uses of magnesium for Cathodic protection purposes, and generally speaking all uses fall under these categories.
Packaged Cast Magnesium Anodes
These anodes fit the mold as the traditional magnesium anode. A cast anode has a length of wire soldered to a connection, and the anode is placed in a bag with a gypsum/bentonite backfill material. The entire assembly is then buried and the wire is attached to the equipment to be protected. Magnesium anodes work relatively well in most soil conditions. The backfill mix helps maintain conductivity to the surrounding soil by retaining moisture. Please check with your corrosion engineer as to your specific soil type to ensure the standard backfill mix is appropriate for your application.
Strap Mounted Cast Magnesium Anodes
These anodes have metal straps cast into the anode and extending out. This allows for a direct mechanical connection to the equipment being protected. These anodes are often used in fresh water waterways on both submerged equipment and vessels.
Extruded Magnesium Rods
This type of anode is probably most commonly known for its application in the water heater business – as each water heater has a length of extruded magnesium (or aluminum in some instances) in it to prevent the tank from corroding. In larger corrosion applications these extruded rods are used inside of large storage tanks or also in fresh water waterways.
If you wish to learn more about applications for American Carbon Magnesium Anodes, please Contact Us.