Rudder Integrity Examination and Questions

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mdidriksen
Rough Carpentry Apprentice
Posts: 50
Joined: Wed Nov 12, 2008 5:15 pm
Boat Name: Calliope Girl
Boat Type: 1971 S&S 34

Rudder Integrity Examination and Questions

Post by mdidriksen »

All:

As some of you know from a prior thread, I dropped the rudder off my boat this winter because the bearings are shot and in need of replacement. I was a bit concerned when I got it down that it might be waterlogged, because it weighed 81 pounds. The rudder has a 1.5 inch stainless steel shaft that is close to 5 feet long, so that in and of itself is heavy, but nonetheless I decided to take a closer look at it. Right away I could see that there was a gap at the top of the rudder post, so clearly some water had gotten in. It also looked to me like there was a lot of filler material at the top of the rudder, and sure enough a little light digging and the top of the rudder was exposed. Weird that this was not covered with fiberglass. See the pics below. When I dug this out, there was some moisture in here and some of the foam appears to be disintegrated. Without much effort I can send a wire clothes hanger about five inches down along side of the shaft and it comes back wet and with some gunk. On the other hand, every test hole I have drilled in the rudder has come up dry and with solid foam. So I am trying to figure out if I can trust this rudder -- i.e., if I dig out the top a bit more and fill it with epoxy and put a layer of glass across the top, am I being foolish? To the extent relevant, if this is the original rudder she is turning 40 this year.

Here are pics:

Gap around the post:

Image

Top of the rudder:

Image

Thanks in advance!
mdidriksen
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Joined: Wed Nov 12, 2008 5:15 pm
Boat Name: Calliope Girl
Boat Type: 1971 S&S 34

Re: Rudder Integrity Examination and Questions

Post by mdidriksen »

Just a quick update. After flipping the rudder over and letting it sit for a couple of hours, one of the holes I drilled in the middle of the blade started leaking water ...
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Rachel
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Re: Rudder Integrity Examination and Questions

Post by Rachel »

My first thoughts were of the stainless. I never like to think about stainless steel that is out of contact with air.... I worry about crevice corrosion. Speaking of which, is that a deep ring of corrosion that I see on the far right hand side of the first photo? (On the exposed part of the shaft?) That alone would give me the heebie jeebies, because I have cut into some propeller shafts that have just a few little "pinholes" of crevice corrosion on the surface, and then it is like an ant farm gallery inside.

I may not be seeing that correctly though, is it is slightly out of focus looking. Is it a groove that is supposed to be there? Or a ring of corrosion/pitting from where it was encased in a bearing or etc.?

On the rest of the rudder...

On the one hand, there are so So SO many "wet" rudders out there, and most of them don't seem to be failing. On the other hand..... some do fail. It sounds like you have stainless steel parts inside the rudder that are probably being exposed to moisture without air. That's never good. It's fairly common for rudders to leak right at that shaft/blade interface as it is a hard place to seal.

I guess.... it's one of those things where if you are the type who can sail without worrying about it, and if you're not going offshore, etc. then you might want to leave it. OTOH, if you are somewhat obsessive, like I am, or if you are going offshore, then you might want to open it up and see what you have, knowing it could be the ol' can of worms. I would absolutely have to open the rudder up, myself; especially with it on the bench already.

Just cutting it open, taking out waterlogged foam, replacing it (with more foam, thickened/airy epoxy, or etc.) and then re-fiberglassing is not a really big/hard job, in my opinion (extra nice that it is on your workbench). But if I'm seeing what I think I see on the top of the shaft, I wonder if you wouldn't be replacing the shaft/web also. Then it's basically doing a whole new rudder.

What have other S & S 34 owners found on their rudders? That would be interesting to know.

Little Miss Cheery,
Rachel
Quetzalsailor
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Re: Rudder Integrity Examination and Questions

Post by Quetzalsailor »

Ohhh, no! Been there. Done that. Actually, on both our boats.

Our LeComte's rudder was made to be hollow and open to the sea. The rudderpost and weldments are 316 Stainless. It was cut open by a PO who foamed it full. The openings were badly repaired and weeped foul-smelling goo. Not knowing what was going on, I re-opened the openings and began digging out the waterlogged foam. Still not in the picture, I cut a face off, cleaned everything, found no corrosion on the Stainless components or welds. Then dried the fiberglass shells against the furnace, repaired the openings, coated the glass inside with epoxy, reinstalled the face, covered the whole thing with epoxy-'glass, and it's been fine for the last several seasons.

Our previous boat was a '72 Morgan 27. Its rudder was like yours, hollow faces foamed full, stainless rudder post. Unfortunately, Morgan did not glass the top at all; they simply covered the foam with gelcoat! I drilled holes all over both faces at 1" on center and left the thing against the furnace all winter. By spring, it was obvious that the rudder was still sodden. I set up a vacuum bag and ran it outside in the sun and pulled on it for a couple days. I epoxied up all the holes, covered the top in epoxy-'glass, covered the whole thing in epoxy-'glass and we used the boat for another 5-6 seasons with no problems before moving on to the LeComte. The Morgan is old enough and consumer quality so I wondered at the time whether the post and weldments were stainless; some Morgans and other boats of the time had stainless rudder posts and carbon steel weldments. Since the rudder did not weep rusty water, I quit worrying about it.
mdidriksen
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Re: Rudder Integrity Examination and Questions

Post by mdidriksen »

Sorry for resurrecting an old thread, but I guess I'm on a roll today documenting boat projects. I ended up deciding to replace the rudder, and set forth below are the details of how that worked out. This all took place in the winter/spring of 2011 and is largely a re-post of material from the S&S34 association website ...

------------------

Thought I would provide an update on this project. After getting the rudder off and doing some inspection, I determined that the rudder was full of water and in fact was constructed in such a way that the entire top of the rudder was not glassed over, just filled with some sort of filler material. This presented the possibility that the integrity of the rudder was compromised due to crevice corrosion. This is obviously a personal choice, but for me I just couldn't get comfortable with the idea of just drilling holes in the rudder and trying to dry it out, without cutting it open to see what was really going on. While most of my sailing is local day sailing in protected waters, I'd like to do the Bermuda race, etc. And once you get to cutting it open, a new blade is likely in order.

So the good folks at S&S hooked me up with a shop in Massachusetts by the name of CSI Composites (http://www.csi-composites.com/) that does a lot of high end, high tech glass work -- e.g., they did all the foils on Puma Ocean Racing's Volvo 70. Jeff Kent, the founder of the business, has been just great to deal with. I dropped the old rudder off and after some discussion it was decided that the old piece of the skeg I had already cut off was not ever intended to be structural, and if I wanted to change the rudder shoe so it wrapped around the outside of the skeg it probably made more sense for Jeff to also re-build the lower part of the skeg. So out came the saw again, and I chopped off another six inches or so of the skeg and sent it to Jeff. He then fabricated a new lower skeg that will be glassed into the existing skeg stump (the new piece has skins that will slide up onto the stump after I grind the stump a bit -- sort of like putting a crown on a tooth), and also fabricated a new rudder. We were able to re-use the original rudder post, so that saved a chunk of cash. In the meantime, Jeff was also able to extend the depth of the rudder by about two inches and reshape it slightly. He sent me some pics today of the state of play on the new rudder. A new rudder shoe and a new middle bearing will also be installed as part of the process. Here are some pics:

Existing skeg stump:

Image

New lower skeg:

Image

New rudder:

Image

I took delivery of the new rudder and skeg in May and set about installing it. This ended up being a pretty big and dirty job, as I had to grind away a significant amount of the skeg stub in order to fit the new skeg on to it. Here you can see the new skeg glued in place with the rudder temporarily installed so that I can align everything properly:

Image

After the skeg was in place, it was strengthened with several layers of carbon fiber, followed by fiberglass and some filler. Here you can see the progression:

Image

Image

After the skeg was installed, I installed the rudder using the nifty new rudder shoe that Jeff Kent at CSI Composites designed and had fabricated. Here is the shoe:

Image

And here is the final product, ready for bottom paint:

Image

The installation included new bearings in the rudder shoe and at the through hull point. I also cleaned up the bearing in the cockpit. The new rudder/skeg combination is about 2 inches deeper than the original. Not only is the new rudder much smoother in its operation, it also resolved a previous problem (apparently due to the worn rudder bearings) whereby the boat would pull hard to starboard under power. She now tracks nicely. All in all, this was a big and expensive job, but it gives me peace of mind to know the new rudder is completely solid.
Figment
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Re: Rudder Integrity Examination and Questions

Post by Figment »

That is freaking GORGEOUS.
Hulukupu
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Re: Rudder Integrity Examination and Questions

Post by Hulukupu »

That rudder shoe is beautiful. Thank you for picking up the old thread and updating it!
David
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