I have a 2001 Bavaria 47 cruiser. When I lifted the boat out at the end of last season, I noticed a drip at the bottom of the rudder. I thought it was just condensation dripping down from the hull / winter cover. So I left things as they were for the winter. Whatever water was in the rudder, certainly froze.
In spring I saw the drip again, read up on the topic and drilled the spade at the bottom. I did not see a fountain release, however the ever so small drip continued (with the frequency of about a drop every five minutes(?), especially in "hot" weather, eg 20 C in direct sunlight), never really settling after a couple of weeks. I plugged the hole with a wooden plug and painted it over with antifoul.
I inspected the rudder for cracks where the stock enters the rudder. There is a hairline crack about 15 cm in length as seen in the image attached below. This is not directly at the rudder post, but at the leading edge of the rudder. The rudder was soda blasted clean then. What I further saw, especially when painting with epoxy primer and in warm weather, was water sweating out of pores in the rudder spade. There were maybe ... 20 of these spots on the whole rudder spade and they never developed into a drip, just small beads of water.
The water that dripped through the bottom tap of the rudder was clear, very salty. The water coming from the pores had a brownish tint to them. Might have been reaction with the fresh paint. There is no rust seen on the rudder stock nor is there any rust colored drainage elsewhere. No leakage from the rudder from where the rudder comes into the hull.
The rudder is likely from Jefa, and I understand that these foam filled rudders being moist is very common. My question is if or what to do something about the moisture filled rudder as I'm planning on starting a circumnavigation with the boat next june?
I'm definitely planning on drilling out the wooden bung at the end of season this year. My marina has a paved dock, so I cannot really fully drop the rudder unless hanging from the crane. I might be able to talk the port into placing me partly on a grassy area. I could drop the rudder maybe 50 cm or so on the paved standard lot. Could dig a hole on the grassy area for a complete drop.
I believe the previous owner (I bought her last year) changed the bearings on the rudder 3-5 years ago, so that should be OK. Thanks!