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Martyr Zinc Shaft Anode 1 1/2



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Martyr Zinc Shaft Anode 1 1/2

Category: > Maintenance & Boat Care > maintenance Tools & Anodes

Martyr Zinc Shaft Anode 1 1/2"(38mm)

For one year in salt water fit the following zinc anodes

Area		Hull	Anodes per Rudder
Up to 28m²	Stud fixed	2 x ZD78B	2 x ZD56
(300ft²)	welded	(2 x ZD78)	(2 x ZD76)
28.1m-56m²	Stud fixed	4 x ZD78B	2 x ZD56
(300ft²-600ft²)	welded	(4 x ZD78)	(2 x ZD76)
56.1m-84m²	Stud fixed	6 x ZD78B	2 x ZD56
(600ft²-900ft²)	welded	(6 x ZD78)	(2 x ZD76)
84.1m-102m²	Stud fixed	4 x ZD72BM	2 x ZD58
(900ft²-1100ft²)	welded	(4 x ZD80)	(2 x ZD77)
102m-148m²	Stud fixed	6 x ZD72BM	2 x ZD58
(1100ft²-1600ft²)	welded	(6 x ZD80)	(2 x ZD77)

For two years in salt water fit the following zinc anodes

Area		Hull	Anodes per Rudder
Up to 28m²	Stud fixed	4 x ZD78B	2 x ZD58
(300ft²)	welded	(4 x ZD78)	(2 x ZD77)
28.1m-56m²	Stud fixed	8 x ZD78B	2 x ZD58
(300ft²-600ft²)	welded	(8 x ZD78)	(2 x ZD77)
56.1m-84m²	Stud fixed	4 x ZD72B	2 x ZD58
(600ft²-900ft²)	welded	(6 x ZD73)	(2 x ZD77)
84.1m-102m²	Stud fixed	6 x ZD72B	2 x ZD78B
(900ft²-1100ft²)	welded	(6x ZD73)	(2 x ZD78)
102m-148m²	Stud fixed	8 x ZD72B	2 x ZD78B
(1100ft²-1600ft²)	welded	(8 x ZD73)	(2 x ZD78)

Fitting and Bonding Sacrificial Anodes

WHEN FITTING ANODES TO WOODEN OR GRP HULLED VESSELS

REMEMBER:

♦ The anode must be position on the outside of the hull below the

waterline.

♦ The anodes should “see” the parts to be protected.

♦ The fixing studs should be located above the bilges.

♦ The anode location ensures the minimum run of bonding cable to the

parts to be protected.

♦ There must be reasonable internal access to the studs.

♦ The anode should not be positioned forward of or in line with Echo Sounding

Transducers or log Impellers.

Hull Anode Installation

♦ Stiffen the inside of the hull where the anode is to be fitted if necessary.

♦ Drill holes to take the fixing studs at the appropriate centres.

♦ On wooden hulled vessels studs should be sleeved or painted to insulate them from the

surrounding timber. When sleeving the stud either use a heat shrink tube or ensure that the

inside of the sleeve is packed with marine grade sealant.

♦ Before inserting and securing each stud assembly, apply a generous amount of sealant to the shank and collar where the stud

touches the hull to ensure a good seal.

♦ Whenever an anode is fitted to a GRP or wooden hull an anode backing sheet must be used to control the wastage of the

anode and protect the hull. The anode backing sheet should be replaced each time the anode is replaced.

♦ Always ensure that the anodes are fitted with MGDUFF Fan Disc Washers under the securing nuts which will help to assure the

contact between anode and cathodic protection system. The fan disc washers and nuts should be replaced each time the

anode is replaced.

♦ Protect the anode fixing studs on assembly with paint or grease inside and outside the vessel.

DO NOT PAINT THE WORKING SURFACE OF THE ANODE

Bonding The Cathodic Protection System

♦ The correct bonding of the cathodic protection system

is imperative.

♦ Use 4mm2 PVC Insulated Multi-Stranded Single Core

Copper Cable or larger.

♦ Ensure that all connections are clean and tight.

♦ The best way to bond the anode to the shaft is by using a MGDUFF

Electro Eliminator as well as bonding the anode to the gear box or

Engine casing.

♦ Insulated Flexible Couplings should be bridged by using a short length

of bonding cable or a copper strap to carry through the contact between

anode shaft and propeller.

♦ Bronze and Stainless Steel Rudders, Rudder Hangings and Shaft

Brackets should also be bonded to the main anodes.

♦ Trim Tabs should be protected with separate anodes.

♦ Do not bond the same anode to ferrous and non-ferrous metals or stainless

steel. Steel Rudders must be protected with separate anodes.

♦ Timber hulled vessels may be prone to electro-chemical decay