overview

The Maddox anode is an internationally accredited sacrificial anode for timber andfibreglass vessels. The patented composite alloy is closer than zinc in mV potential to the submerged metals found on most boats making it less aggressive on coatings and parts than the zinc equivalent.

Zinc anodes are for steel, aluminium and cast iron. Maddox anodes are for stainless steel, copper and bronze.

Downloads : 

• Anode Selection Guide based on vessel type 
• Identifying Corrosion types with example images 

Anode Selection Guidelines:

Selection and Installation – The appropriate size anode for any one vessel depends on the type, volume and surface area of the submerged metals to be protected.  The anode consumption rate can be calculated with reference to DNV-RP-B401. Maddox anodes available in MAD1.6 MAD2.5 MAD4.2 Maddox anodes are manufactured without holes to allow custom fitting of the anode to any vessel.

• 20-45ft
  • 1 shaft: Maddox Anode MAD1.6*
  • 2 shafts: Maddox Anode MAD2.5*
• 46-75ft
  • 1 or 2 shafts: Maddox Anode MAD4.2*

*Notes:

1. Assuming stainless steel, bronze and copper submerged metallic fittings
2. Use tinned copper bonding wires
3. Stern drives / Outboard Motors / Sail drives (Aluminium Cast Alloy)
   1. Fibreglass, wooden & carbon vessels should use OEM zinc anodes
   2. Steel & aluminium vessels should use zinc anodes calibrate d and tested to the original design

Options:

• MPS Maddox Anode 1.6 - Sacraficial Anode - Protection for Timber and Fibreglass Vessels - Stops Wood Rot in Timber Vessels (MPS MAD1.6)
• MPS Maddox Anode 2.5 - Sacraficial Anode - Protection for Timber and Fibreglass Vessels - Stops Wood Rot in Timber Vessels (MPS MAD2.5)
• MPS Maddox Anode 4.2 - Sacraficial Anode - Protection for Timber and Fibreglass Vessels - Stops Wood Rot in Timber Vessels (MPS MAD4.2)
• Tricab Marine Green Single Insulated 10mm² Tinned Copper Bonding Cable-Wire (SUR TRI T10GR)
• MPS Marine Propeller Shaft Stainless Steel Grounding Strap (MPS.SS07)
• MPS Electrolysis Blocker - Galvanic Isolator 67Amp (MPS EB67W)
• MPS Marine Propeller Shaft Stainless Steel Grounding Strap (MPS.SS07)

Cathodic Protection Bonding Systems provide for an electrical connection to carry low voltage galvanic current, simply wiring all the vessels below water metals together. The differing potentials (or voltage generated in water) are equalized. The integrity of the bonding system and the components used in the bonding system are very important to ensure that there are no deficiencies in the system.

There are many different compositions of wires and lugs used by Marine electricians. Some of these materials are not effective for use in a bonding system and as such the galvanic current is not carried. Additionally of there is a break in the bonding system such as a faulty connection or damaged wire it can also leave the vessel inadequately protected.
Some simple measures to consider when constructing a bonding system:

• Tinned copper cable (fine strand) is required for the bonding wires. Depending on the distance between connections and the metallic fitting connection, a 6mm2 to 10mm2 should be adequate.
• The eyelets for the bonding wire ends must be fabricated from electrical quality copper and then electro-tinned.
• High quality stainless steel 316 busbar.
• Through hull fittings should be matched to gate valves, for example a stainless steel 316 through hull fitting should have a stainless steel 316 gate valves. The use of dissimilar metals (for example a stainless steel through hull fitting with a bronze gate valve) promotes galvanic activity.

This material remains the exclusive property of Marine Protection Systems Pty Ltd and must not be reproduced, replicated, copied or used without the expressed consent of Marine Protection Systems Pty Ltd © 2011

Ref: Tips for Bonding Your Vessel – Marine Protection Systems

specification

Standards

• ABYC E-2 Cathodic Protection. Sec 2.5.1
• DNV – RP-B401 CP Design. Sec 1.1 & 6.3.5