ProMag Specialty Magnesium Anodes for Cathodic Protection by Farwest Corrosion

Farwest Corrosion Control offers a complete line of specialty cast and extruded sacrificial magnesium anodes for a variety of uses. These anodes can be submerged in fresh, brackish or seawater environments. Many of the anodes are available with an optional Plastisol coating designed to be cut away from the anode, limiting surface area contact and current output.

Galvanic Efficiency

Anodes are produced to H-1 or AZ-63 specifications and have a current efficiency of approximately 55% in seawater with a current capacity of 550 amp/hour per pound. Open circuit potential of this alloy is nominally -1.55 volts with respect to a copper-copper sulfate reference electrode.

Chemical Composition (%)

Applications

Farwest's magnesium anodes are effective and economical corrosion fighters that for over 25 years have been protecting a variety of steel structures in a wide variety of environments, including salt, brackish and fresh water:

• Hulls of ships, barges, tugs and boats
• Ballast tanks of ore carriers and similar vessels
• Bulkheads
• Water storage tanks
• Piers and pilings
• Pipelines
• Heat exchangers
• Traveling screens 

1.	The surface to which the anode is to be attached should be cleaned of scale and rust by chipping and wire brushing before the anode and/or mounting kit is to be installed. This is important to insure a good seating surface for the anode.
2.	When installing to a steel surface, fillet weld the tapered end of the #304 stainless steel stud with a 1/8” diameter #310 stainless steel electrode at 70-105 amps. The stud must be held perpendicular to the steel surface and a neat weld should be made without building up an excessive reinforcement, otherwise the anode will not seat squarely against the surface to be protected.
3.	After the stud has cooled, place the 1/16” x 10” x 10” rubber sheet over the stud and lay flat against the steel structures surface. Do not tear or enlarge the stud hole in the rubber sheet.
4.	If using a “resistance washer” in the installation, slide the rubber insulating tube over the anode stud until it comes in contact with the rubber sheet installed per item 3 above. If you’re not using a resistance washer in the installation, do not install the rubber insulating tube.
5.	Apply enough gasket sealer compound (included in the anode mounting kit) to coat the bottom face of the anode. This compound can be applied with a putty knife, spatula or similar.
6.	Place the anode in position over the stud and on the rubber sheet. Insure that the anode is not in direct contact with the structure’s steel surface.
7.	Place the provided steel flat washer over the anode stud and allow the washer to contact the anode core inside the anode recess. If using a resistance washer, do not use the steel flat washer. Instead, install the resistance washer in place of the steel flat washer.
8.	Install the ½” Flex-Loc nut on the threaded portion of the anode stud and tighten the nut to secure the anode. If using a resistance washer, do not over tighten the Flex-Loc nut as it may crack the resistance washer.
9.	Liberally coat the stud protector gasket with gasket sealer compound and then place the gasket over the anode stud and into the anode recess.
10.	Screw on the ½” plastic anode stud protector until it seats against the rubber stud protector gasket. Do not apply excessive torque or the plastic will crack.