Moisture in rudder, ok or not?

[UP]

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!

[Yngmar]

We've had the same. Advice from an experienced fibreglass boat builder was: it's normal, don't worry about it, let the water out whenever you're on the hard.

Advice from Jefa is to seal the likely ingress point around the shaft like this: https://www.jefa.com/ftp/rudder/maintenance/Rudder_blade_anti_fouling_instructions.pdf

Our rudder was from 2000/2001 and from JP3, not Jefa - likely so is yours, the switch was only a few years later I believe. The JP3 rudders did never have any sealant around the shaft top from new.

We didn't have a crack at the front, this I would grind down to the fibreglass and see if it goes deeper than gelcoat, if so, lay up some glass there. If not, just patch the gelcoat.

To let the water out, I drilled a hole at the start of the haulout and let it drip. It stopped pretty soon. But I had a vacuum pump on board for refrigeration repairs, so I stuck the hose from that into the hole in the bottom of the rudder, with a catchment bottle and got about half a liter (I think) out that way, as it sucked the water from the foam. After that I did the top seal and also closed the drain hole (not with a wooden bung, with epoxy).

We also had the "pores", which are blisters that develop from the water on the inside, not osmosis from the outside, although they do enter the fibreglass substrate and get a vinegary smell. They should be ground out and patched after letting the water out of the rudder. I left that job for the next owner

Or go sail in orca territory and then make an insurance claim 

[UP]

Dear Yngmar,

Thank you for the super-informative reply! I'll work on the rudder once the season is over and the boat is out again. The Jefa page is useful too, I can take some measurements with my multimeter and make double sure to passivate the rudder stock against corrosion.