ProMag Specialty Magnesium Anodes for Cathodic Protection by Farwest Corrosion

For use in Water Tanks, Condensers, or Similar Applications

Specialty Magnesium Anodes

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 (%)


H - Grade B


5.3 - 6.7%


0.15% min


2.5 - 3.5%


0.30% max


0.05% max


0.003% max


0.003% max


0.30% max




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 
Installation Instructions for Condenser Anode with Mounting Kit

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.
Magnesium Condenser Anodes

Magnesium condenser anodes are used in many different applications such as tank interiors, condenser water boxes, heat exchangers, etc. These anodes are produced in a number of shapes, weights and configurations to meet customer requirements.

The popular model C-15 has a nominal weight of 15 pounds with a 3/4" galvanized steel pipe core. This anode can be furnished either bare or with an optional Plastisol coating.

Ordering Information
Model Part No. Weight Size Core Type
C15 01-13020 15 lbs 8" x 8" x 4"

Cast-in galvanized 3/4" steel pipe core

C7.5 01-13015 7.5 lbs 8" x 8" x 2"
2R5 01-13014 2.5 lbs 5" dia x 2"
2R5 01-13016 2.5 lbs 5" dia x 2"

Cast-in galvanized 1/2" steel pipe core

2R5 01-13012 2.5 lbs 5" dia x 2"

Drilled and tapped for 1/2" x 13 bolt

Flush Mount Hull Anodes

Hull anodes are a popular solution for many submerged cathodic protection applications. Available with cast-in steel mounting straps, hull anodes can be either bolted or welded directly to a submerged structure. Applications include barges, ships, dams, tanks, piers, pilings or similar structures.

H-22A:  Popular anode weighing about 22 pounds. Contains two cast-in 1/4" x 1 1/2" galvanized steel straps that are easily welded to the steel hull structure. A Plastisol coating is available as an optional current barrier.
ML-5 Launch Anode:  Weighs about 5 pounds and contains cast-in galvanized steel straps with two 5/8" holes for mounting. Widely used on steel hull service boats.
H-24W:  Weighs about 24 pounds and contains two cast-in 1/4" x 2" galvanized steel straps.

H-44W:  Weighs about 44 pounds and contains two cast-in 1/4" x 2" galvanized steel straps.

Mounting holes are provided as an option, as is a Plastisol coating used as a current barrier.

Ordering Information
Model Part No. Weight W L La H Core Type
ML-5 01-13324 5 lbs 5" 10" - 2-½"

Cast-in galvanized steel strap, 14-¼" long

H-24W 01-13081 24 lbs 9" 18" 8" 2"

Two cast-in galvanized steel straps. Mounting holes and Plastisol coating are optional.

H-22A 01-13079 22 lbs 10" 20" 10" 2"
H-44W 01-13084 44 lbs 9" 18" 8" 4"
Pier Anodes

Built for a number of applications, pier anodes can be suspended in water environments or installed directly onto the seabed or lakebed. The relatively large magnesium content provides longer anode life. Anodes are available with either a steel eyebolt or pipe core.

  • Pipe: ¾” galvanized steel pipe core extending 1” beyond anode ends
  • Eyebolt: ½” diameter galvanized steel eyebolt core. ¾” diameter for 200 pound anode.

Farwest can install a specified length, size and type of cable for attachment to the structure.

Ordering Information
ModelWeightSizeCore Type
MG-P-50C 50 lbs 8" dia x 16" Pipe
MG-P-50C 50 lbs 8" dia x 16" Eyelet
MG-P-100C 100 lbs 8" dia x 32" Pipe
MG-P-100C 100 lbs 8" dia x 32" Eyelet
MG-P-200C 200 lbs 12" dia x 27" Pipe
MG-P-200C 200 lbs 12" dia x 27" Eyelet
Tank Anodes

Primarily designed for tank interiors, tank anodes utilize a longitudinal steel strap core for bolting or welding to the steel surface.


ModelWeightWHLaLcXCore Type
T36 36 lb 4" 4" 28" 38" 36"

Longitudinal, galvanized
steel core, 3/8" x 1-½"

T-52A 52 lb 5" 5" 29" 38" 36"
T53 53 lb 7" 7" 16" 24" 22"
Model T-57 contains a cast-in, galvanized steel core 3/8" x 1 3/4" with 11/16" dia. mounting holes.

Model DC-60 contains a cast-in galvanized steel core 3/8" x 2" with 13/16" dia. mounting holes.

ModelWeightWHLaLcX Y Core Type
T-57 57 lb 7" 7" 16" 21" 19" 8"

Longitudinal, galvanized
steel core, 3/8" x 1-¾"

DC-60 60 lb 6" 6" 30" 21" 19" 10"

Longitudinal, galvanized
steel core, 3/8" x 2"