Rudder problem?

[mgphl52]

They don't look very good to me... If this is a boat you're considering to buy, I would highly suggest having a good surveyor check it out.

[JD-MDR]

It could be coming from above if there is an iron a bracket or something like mine had. This was actually easy to fix. See earlier post

[John Stone]

John B. John Stone here. A “good surveyor” can save you a bundle. There can be problems that his report can, best case, help you leverage a better purchase price. Worst case you might get an idea of what is headed your way.

There is a steel bracket above the rudder post in the space below the cockpit floor. Maybe that’s it. Maybe not. Hard to say from just those photos.

[Bill Goldsmith]

As mentioned, could be water that dripped from above, or water that welled up from inside the rudder and dripped down. 15 years ago my surveyor said my rudder tested moist, but rather than condemning the rudder he recommended drilling weep holes during the off season to let it drain and dry out. He said to keep a close eye on it for signs of internal corrosion damage to the steel frame (play in the rudder) or cracking that could indicate water freeze/thaw. After letting it winter for two consecutive off-seasons with a swiss cheese of weep holes, and subsequent epoxy injections, it seems to be holding up just fine and solid today. As mentioned, hard to tell from your photos whether it's an easy solution like mine, whether it's not the rudder at all, or whether the rudder is suspect. If you don't want to get it surveyed, maybe just get a well respected boat mechanic/fiberglass expert to take a look at it--at least you'll be going in with eyes open.

[sgbernd]

For what it is worth, mine looks the same when hauled and has for the 17 years I've owned her. It makes me worry but I've not had any problem yet. The rudder may be wet and the rust may be coming up out the shaft but I don't see why it keeps seeping for many days like it does. I keep watching this forum for rudder failures but since I don't see them which is positive.

Steve Bernd

[Bill Goldsmith]

Thanks for the input. If I purchase her I'm dropping the rudder. If you look closely and view full size it looks like the glass is separated around the shaft and the rust stains emanate from there. At 40 years it seems like a maintenance item, once verified we can sail to distant shores knowing our rudder is one of the stronger links in the chain.

When I was researching a 330 last spring the seller had a new rudder built, he published contact info for the builder who was going to store the mold. Is there any such thing for the 36's?

Thanks again,
John

Search on this board for "Foss Foam" and I think you'll find some helpful discussions. Their web site looks good as well.

[John Stone]

As noted I documented how I rebuild the rudder on the Far Reach. The rudder was split wide open along the bottom from one end to the other with a ghastly crack. I routered out the top where it fit around the rudder post and poured in thinned then thickened epoxy to seal it to the rudder post. I sealed the bottom crack by grinding it open and beveling both sides of the crack. I filled it with thickened epoxy and strengthened it with multipllayers of 17.08 biaxial. Since then I have sailed the boat over 5000 NM, the vast majority offshore. I have had no further issues. I am satisfied and confident in the rudder. I doubt you need to spend thousands on a new rudder. I suspect all you need to do is rebuild the one you have.

Worst case, use a 4.5”’ right angle grinder with a metal cut off wheel and cut it in half along the outside perimeter all the way around. Then take the two parts halves apart and see how the shaft looks. Then, if happy with it, glass it back together with epoxy and biaxial tape. Reinstall.

[Matt Cawthorne]

Some more information on age and model might help. For instance on the 36 of early 80s vintage there was nothing above that could drip down that was made of ferrous material. I pulled my rudder several years ago with the intention of removing the glass and 'foam' around the top of the shaft and giving it a good inspection. When I got inside I was not pleased so I scrapped the rudder and built a new one. The crevice corrosion had eaten some holes in the shaft that were enough to worry me.

The rust stains around the top are a hallmark of crevice corrosion. In an oxygen deprived, saline environment, iron can dissolve from a locally non-passivated surface and form chlorides that wander around in the solution until they find some oxygen (where a crack meets the atmosphere or water). When they get there the iron in the chloride attaches to the oxygen freeing up the chlorine to go back and get some more iron. The iron oxide is what you are looking at on the surface. Once the process starts, the chromium oxide on the surface of the part has a different voltage on the galvanic scale than the non-passivated pit that develops. The pit becomes more disadvantaged in that it effectively is part of a battery with the pit forming the dissolving electrode. The process accelerates and the pit grows down into the metal. Even if the stainless shaft were passivated completely and properly, a simple nick or scratch is enough to break the chromium oxide surface layer.

When I was rebuilding my rudder I wanted to know what was in the old rudder for structure. It was some sort of polymer (perhaps polyester) with some fillers that formed the bulk of the rudder. I took a piece of the skin and burned off the resin to examine the fibers. The reinforcement on the surface was random glass mat, and not very much of that. Perhaps one or two layers.

My recommendation would be to plan on the cost of a rudder replacement and make your offer accordingly.