How to Choose A Marine Rudder Bearing
How to Choose A Marine Rudder Bearing
A Marine rudder bearing is one of a sailing vessel's most important and overlooked steering components. They play a vital role in preventing rudder binding and improving steering feel. When they become worn, a rudder will often turn much stiffer and feel less responsive. Like maintaining a flexible disc coupling and marine engine boards, it can be hard to tell when a rudder bearing is failing, so it is best to inspect the rudder and bearings every year and at each haul out.
Here are the things you must remember in selecting one:
Where is the Rudder Bearing Located in a Ship?
The rudder bearing, also called a rudder stock or a rudder tube bearing, is in the rudder log, positioned inside the boat's hull.
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How to Choose A Marine Rudder Bearing
Most rudder logs incorporate a rudder bearing and a stuffing box, a hollow tube filled with rings of wax-infused material, known as flax packing, that forms a seal with the rudder stock and the hull and prevents seawater from entering the system.
Rudder Bearing Components
Rudder bearings are made of various materials, including stainless steel, aluminium, and abrasion-resistant plastics.
In general, stainless steel is preferable because it provides the best corrosion resistance and a good service life. But stainless steel is a slippery metal that does not adhere well to composite rudders. It is not recommended for use with composite rudders because of the increased risk of corrosion and eventual failure of the rudderstock.
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How to Choose A Marine Rudder Bearing
On the other hand, Aluminium is a superior choice for rudder bearings because it has excellent corrosion and fatigue resistance. While aluminium is more expensive than stainless steel, its durability and strength make it a worthwhile investment. Many newer vessels feature aluminium rudderstocks and rudder tubes. One of the best materials to mould rudder bearings from is Polenite, a highly engineered heat cured polymer alloy. This product is newer to the rudder bearing market and its use is becoming more widespread due to its performance and value for money.
Tips to Remember
● Suppose your vessel is fitted with a fiberglass or resin rudder. In that case, you should consider replacing the metal pillow block style bearings with an alternative, preferably a highabrasion, tolerant, and low-friction polyethylene bearing.
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How to Choose A Marine Rudder Bearing
● The non-metallic sleeve and roller bearings typically found in many nonhydraulic rudder systems are easy to replace, inexpensive to manufacture, and require no maintenance.
● The rudder stock should be mounted in such a way as to minimize metal-to-metal contact between the rudder bearing and the rudder stock.
● The material of the rudder bearing should be selected with the best possible abrasion resistance, thermal stability, and chemical resistance in mind. It should be galvanic compatible with the aluminium rudder stock.
● The rudder stock should be swaged to avoid excessive strain on the rudder bearing and allow for easy access in case of future repairs or replacement.
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How to Choose A Marine Rudder Bearing
In searching for a replacement, get help from an experienced technician and only buy products from a reputable company like Poly Flex. Visit their website to learn more.
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How to Choose A Marine Rudder Bearing