rudder vibration

[alex mercurio]

i could use any ideas or insight into a vibration i get that comes from the rudder. whenever i sail my boat at speeds between 8.5 knots and 9.5 knots i get a vibration coming up from the rudder. i know this because i have put my hand on the quadrant and it vibrates very strong. the dealer says that the rudder may nead "fairing". has anyone experienced this problem? could it be anything else, such as rudder bearings or post....? please feel free to call me at 805 857 2092 thanks, alex

 

[Mike]

Just some thoughts on the rudder vibration issue. How long have you owned the boat?Has it always done this or is it recent? If it's recent have you hit anything with the rudder that might have mis-shapend it?The rudder stock is a composite material and it's unlikey it's the problem.How clean is the prop?I have an Autoprop on my 361 and if it's loaded with barnacles or one of the blades needs greasing it can cause vibrations at the rudder. Seems as though the flow of water off the prop is uneven and can cause vibration.

 

[alex mercurio]

mike, thanks for the reply. the boat is new (06'). i noticed the vibration right away. have checked the prop, it's a 4-blade folding volvo penta prop. rudder is clean. again, seems to start vibrating around 8.5 knots up to 9.5 knots. what does proper fairing entail? alex

 

[Mike]

Rudder fairing

Alex rudder fairing is where they would reshape and smooth the lines of the rudder so the water will flow past it without causing turbulance. Out of curiosity does it do it when both sailing and motoring?Mike