Lavezzi 40: Rudder Gone . . .

[Patacha]

Hi. I lost my STB rudder without even feeling it... It broke just above the lower rudder bearing. Has anyone else heard about such a problem, or I am the only winner...?

Ron

[barnakiel]

What part broke? The shaft (post)? What metal was it made of?

I have seen them bend, but not break!

Interesting. If it was not impact related you might like to replace the other one too.

b.

[Patacha]

The shaft broke (I think... - I was not there; it looks so). See picture. I thought it was SS but juding by rust, it may be steel. I spoke to the service with FP; the kind woman said it's Alum - but I seriously dout that. She quotes Eur 1,250 ex-work; 4 weeks (!) leadtime! I have no clue when I've lost it (it is a Cat with another rudder agter all...:-). Another good reason to buy a Cat; Rudder redundancy! LOL

[David M]

A good yard can fabricate you one out of the correct material. I would not purchase the same exact rudder made from the same materials from the manufacturer until you know the cause.

You may have an electrolysis problem which may not be the fault of the manufacturer. Have someone at the yard examine the problem or hire an expert locally to have a look.

[barnakiel]

Whoa. What about the other one? Have you inspected it?

b.

[barnakiel]

Originally Posted by David M

A good yard can fabricate you one out of the correct material. I would not purchase the same exact rudder made from the same materials from the manufacturer until you know the cause.

Well said. Probably better to make the replacements from known materials. A local boatyard can probably make them for you from based on the remaining one.

b.

[Patacha]

Thanks. The plans in the Owner Manual say INOX 16mm, but I have to hear word from the yard what is left in there... Interestinglly enough, the tube around the post is made of Aluminum, but I don't think they are in contact (they are connected via the plastic bearing - so electrolysis is not likely...

[Rapanui]

There is a danger here of over reacting. Lavezzi's have done many tens of thousands of ocean cruising miles and this is to say the least unusual. The most likely root cause is either that the rudder was grounded/hit something in the past or there is a fault such as electrolytic corrosion. Our Maldives had a rudder break because of a rock incident when in charter. It did not break immediately but some time later through fatigue. Our Athena has done over 35,000 nm on its original rudders in charter. It would be interesting to know the boats history

[bill good]

It looks like rust. A inspection of how the other rudder is made about now should be carried out about now!!
Yes two is good.

Regards

[barnakiel]

16 mm is not all that much, so probably the choice of shaft material is of utmost importance. I understand rudder loading is very small on a cat.

My own boat had a 20 mm inox shaft in windvane's rudder and this snapped too and more than once.

I think aluminum and steel do not have to be in contact to corrode once salt water is present. But this actually would give trouble to the aluminum part, not the steel one.

b.

[Eleven]

I lost a rudder on my Prout. The bottom bearing bracket failed due to not having anti-cathodic protection (zincs). What was left had little weld remaining (it's chemically and electrically always different to the parent material and must be protected from electrolytic corrosion.
The replacement was made by a local yard with a pillar of the right grade of stainless steel running from top to bottom bearing. The GRP casing was cast from the 'spare' one on the other side. I had two made, as the old one was probably of the same design.
The GRP shell and it's enclosed bar were then filled with closed cell foam to seal the structural member, prevent any possibility of osmosis, and add additional strength.
Quote was for 4k sterling but came out a little cheaper than that. They looked good, and I did see them fitted after I'd sold the boat.
This may all seem over the top in view of some comments, but the advantage of having two rudders is that you always have a spare one, but only while you've still got two.

[Patacha]

Hey Guys, thanks for the input.

FP Acknowledged it it INOX posts; weird; I'm gonaa' fly out to the boat this weekend and see for myself. I don't think it's 16mm; it must be 20mm or more.

FP quotes Eur 1,350; I've asked the yard to quote as well.
It looks like some Eur 4K job in total between the rudder, hauling, yard, shipping and taxes...:-(

[colemj]

It is unlikely the rudder post is 16mm diameter. I suspect it is more like a 50-60mm diameter tube with 16mm wall thickness.

Mark

[fgd3]

I lost the rudder on my Hunter 25 about halfway between Key West and Havana. The shaft broke much as yours did. The construction looks similar. The shaft was a thinwall stainless steel tube filled with a dense polyurethane foam. The hard filling kept the tube walls from buckling under bending stress. Unfortunately, the stainless steel corroded and when the wall of the tube was weak enough it broke. The foam filling didn't provide any strength once the wall was torn and the rudder quickly broke off and floated away.

I was able to lay a course to Key West with sail trim. When I got there I built a temporary rudder around a galvanized steel pipe. I wrapped it with fiberglass to build it up to the diameter I needed. I filled it with foam to keep water out during the installation, and a fabricated a rudder blade from plywood, foam, and fiberglass. That was in 1993 and I never needed to finish the "permanent" rudder which still resides, partially completed, in my garage.

I removed the old rudder shaft and installed the new one with the boat in the water. Since the rudder blade was buoyant I had to use my weight to force it deep enough into the water to align the shaft with the rudder tube on the boat. I've forgotten how I managed to avoid getting pinched between the top of the rudder and the hull. There's a potential risk of injury if that happens.

I don't know if my experience would scale up to your boat, but my cost for replacing the rudder was under $100.

Fabbian

[sww914]

16mm is smaller than the diameter of my thumb. My Nacra catamaran had pintles that size. Somebody gave you some bad information.