Have I got a rudder problem?

[Roger Long]

I'd like to call this meeting of our metal and corrosion experts to order. Rich, Bill, Mainsail, please move your chairs up to the front.

Like 98% of foam filled rudders over a metal frame, mine leaks. There is just no way with those strains to keep things tight where the shaft goes into the fiberglass structure. The boat came with some ice damage so I pumped epoxy into the large raised blister and installed a plug in the bottom.

Every fall, I remove the plug and water drains out until the hard freeze but I've avoided further water damage. The rudder has little hairline cracks in the gelcoat that don't appear structural but show up as wet lines. I grind them out as I find them and glass them.

A couple of days ago, I noticed that the cracks all had become rust colored and the bottom of the rudder around the drain hole (which I put the plug in a couple weeks ago) was stained rust colored. This is new. The water coming out the rudder has always been clear.

I'm wondering if something has changed in the corrosion metallurgy of whatever is going on inside the rudder. I haven't been able to get any intelligence on the rudder construction but I wouldn't put it past Endeavour to have used plain steel for part of the interior web on the theory that it was getting covered with foam and glass.

If I scrape the paint off one of the rust streaks down to the crack, I don't see any rust color in the cracks which are hairline. Possibly, this is an interaction of the copper in the bottom paint with whatever kind of chemical soup is seeping out of the rudder.

The rudder feels solid on the shaft but I'm wondering if I need to cut into it now and find out what's going on. Tough decision because it probably means delaying my departure a week or two and I'm already running behind.

I'm not 100% that I'm sure what I'm seeing is rust. It's the light color of the rust that shows up on stainless or in rusty water pipes. I'm trying to figure out why it would suddenly start showing up now.

What do you think? Watch and wait and plan a haul out down south next winter or bite the bullet and get out the hole saw now?

Here are pictures:

 

[Ken13559]

I know nuts about rudder & material science so I'll just sit behind and enjoy the coffee and cup-cakes. Thanks for the invite.

 

[mcrow33]

Roger, here is some information that I found about Endeavour rudders. This was posted on the Endeavour owners website.

Here's the contact info for the guy who made/makes the Endeavour rudders:
Foss Foam Products of FL Inc
Clearwater, FL 33762
(727) 571-3626
www.newrudders.com
Talk to Al Walker
A gentleman by the name of Chuck Foss developed a high density foam, and with it in the 1960's, started FOSS FOAM PRODUCTS. In 1978 Bob Walker (Al's son), who up until then worked for a company next door to FOSS, helped move FOSS to Clearwater, Florida. Once set up in Florida Bob began soliciting contracts from boat manufacturer's to build their rudders by going door to door with a sample rudder and letting people try to destroy it with a sledge hammer. Apparently it was a very convincing demonstration.
Before the FOSS process hit the scene rudders were typically manufactured using a resin and filler material in which the two halves of the rudder were first manufactured. Once the halves were made they were then sandwiched together with the SS rudder stock and its blades using more of this resin/filler material to effectively "glue" all the pieces together. The problem with this process was that because large quantities of this material were used, it was susceptible to cracking and splitting. This would of course allow water in and begin the deterioration process. Also, because water got inside all the metal rudder components had to be stainless steel so that it wouldn't deteriorate as well.
According to FOSS the advantage to their process was that their rudders were lighter, were very strong, weren't susceptible to the water migration issues, and were much less expensive. They also use a solid plate with a continuous weld rather than separate blades inside the rudder.
Anyway, Endeavour gave the contract to FOSS to build the rudders for the 32, 33, 35, 37, 38, 40, 42, and 43. They still have all the molds for the Endeavour rudders and build replacements for them. They also build rudders for many other boat manufacturer's

 

[woodster]

thanks for posting this info Macrow33......i see that they made the 9.2 s2 rudders as well...so am i to assume that if they made my rudder that it is the best that can be had and i will prolly have no problems with my rudder baring that it has not been hit or breached in some way...what is you opinion

regards

woody

 

[Ed Schenck]

My Foss rudder was once waterlogged. I was successful in building up the entry, where the post enters at the top, with an epoxy paste. I never had rust but for most of its life it was in fresh water. Stainless will rust, especially in salt water.

In 2008 I had the rudder rebuilt after a slight mishap on the way to Florida. The yard said the stainless was excellent. They also said the foam was subgrade with voids. I didn't see it so take that for what it is worth.

 

[Bob J.]

Roger,

The boat in Mass that I discussed w/ you had that same problem in addition the rudder had fallen on the pintle. Given your plan, might be time to consider a rebuild/replacement.

 

[Roger Long]

in addition the rudder had fallen on the pintle.

These boats don't have any kind of carrier bearing. The large washer between the rudder and the lower pintle is the carrier bearing. Mine isn't perfectly square so the rudder actually goes up and down a bit as it swings but it hasn't cause any problem that I can see.

 

[kloudie1]

I won’t help with the decision making, but here is what I would consider .. The rust stain is probably exactly that .. rust. It is most likely from salt water attacking the welds and heat affected zones in the base metal where the frame is welded together and to the post. The frame was most likely not made of an “L” grade 300 series stainless and the heat of welding has most likely caused sensitization in welds and heat affected zones. This will make those areas much more prone to corrosion than the rest of the base metal. NOW.. Since the rust just recently started showing up, the damage is most likely not severe enough to be a danger immediately, but probably should be addressed in the next couple of years. One way to better assess would be to drill a hole in one side about 2” in diameter where the frame meets the post .. Then you could look at the weld area .. and it would be easier to plug back up .. Considering the strength of stainless, and the probable amount of welding on the referenced plate versus a frame, a little rust stain is a warning but the sky (probably) isn’t falling yet..

 

[Roger Long]

I just added photos to the OP. I'm not 100% sure this discoloration is coming from the inside.

 

[kloudie1]

My peanut gallery comments again: I think rust; and from the small amount of it, and the fact that it has only recently shown up, I am more convinced that you have a problem but it most likely won't fail this season.. (I was sure of that for the toggle replacement too :~) ) Going to have to be addressed sometime in the next couple of years..
Thinking that water is getting in at the pintle/fiberglass interface.. the bracket that is welded to the tube in there has, recently (Couple or three seasons), begun to corrode.. Doesn't take a whole lot of good stainless to handle those loads, so if there is a plate and not a frame, ya probably have enough stainless for a season or so.. (but I would be tempted, given your long range inclinations, to gouge out the place where you've ground a very little and see what the stainless looks like at the weld)

 

[Eric M]

Roger,

I am with Claude on this one, I don't think the sky is falling yet. You have been dilligent about trying to keep up with the cracks and keeping the rudder as water tight as possible and draining out any water you can.
To determine if the rust is coming from the inside or not I think you need to carefully grind out the cracks as it appears you started to in your photos above, either you will find no evidence the rust is coming from inside the rudder or you will find one or more areas where no matter how deep you grind you still see evidence of the rust coming from inside the rudder.
I am definately interested in what you find as during our last haul out I too found signs of water inside our rudder. I have been bouncing a bunch of ideas around in my head how to tie the two sides of the rudder together around the internal frame with fiberglass and epoxy to further strengthen it.
I would sure like to see a photo of the plug you created and installed in the bottom of your rudder.
Let us know what you find.
--Eric

 

[Roger Long]

I would sure like to see a photo of the plug you created and installed in the bottom of your rudder.

It's too late to photograph but was dead simple. I got a 1/4" S.S. "T" bolt, the things with the pointed flange on the head, for driving into wood. I drilled a deep hole in the bottom of the rudder upwards to make a drainage space and then tapped the fitting in, pulled it out, and drilled where the prong indentations were. I then set it back in bedded in epoxy with a long, waxed, temporary steel bolt. The plug is a long S.S. set screw. I usually epoxy over the set screw after I put it in because it's easy to chip away the next fall to reach the bolt. I didn't do that this year because, despite extensive patching of what I can reach, the rudder is basically a screen door on a submarine.

Here's my fall back if the sky should fall:

 

[Bill Roosa]

Well Roger, what does the rust taste like. And yes I'm serious. Rust tastes like rust and not like some toxic chemical brew.
WARNING, WARNING Will Robinson, do not eat the rust colored snow.... (could not resist)
The picture is very pretty though, lots of contrasty colors.
As for why this is happening, that is simple, you are about to embark on a trip and something has to keep you up at night. In the words of Jim Lovell during the Apollo 13 take off when the center engine of the second stage shut down early, "I think we just had our glitch for this mission" So since you will be watching this it will have to be some other system/item that "blows up" and wrecks your day. Just don't stir the O2 tank and you should be ok.

 

[RobG]

Same deal with me Roger. When I purchased my E28 a couple of yesrs ago I noticed rust coloured weeping coming out around the rudder shaft during my survey. A moisture meeter confirmed a saturated rudder. I focused on this during the pro survey and the surveyor (been around a LONG time and highly respected) said "yup, there are a lot of saturated rudders out there - don't worry about it - go sailing". Most rudders have a lot of SS in the framework and there would be a lot of corrosion to happen before the frame would be comprimised.
I did the same thing you did and added drains in the bottom. Not much water came out and the moisture meter still read saturated even after several months. The foam really holds on to it. If you did go the rout of "fixing" it you'd probably have to do a complete fillet job on it, not something I would enbrace at this point anyway. Does it still bother me? Yup, but it will have to wait until another day (year - decade?). Bottom line - a surveyer with a lot more experience sain not to worry about it.

 

[Don12364]

Yes, I believe you have. Your rudder is cracked. And if those cracks penetrate deep enough for liquid to seep out then there must be a question of structural integrity never mind the rust.
Also where else could the stains have come from if it isn't rust?

How about glassing them over for the time being to prevent further extension of the cracks and to reinforce that area as well.
Then an amateur proof test of the rudder by fixing the helm and pulling or pushing with all your might on the blade to see if the internal structure fails.
If it doesn't - good. It may be strong enough.
If it does - good. Your life may just have been saved.

 

[Roger Long]

Also where else could the stains have come from if it isn't rust?

Good question. However, the water that ran out of the rudder last fall was clear. There was no rust spot on the ground. I've been down to the boat almost daily since early winter. I've looked at the rudder because I've been going over everything else. These streaks didn't show up until about a week ago.

 

[Ross]

I have been working in a house that is supplied by pipes from a spring a couple of miles from the house. The water runs clear but when it runs slowly the desolved iron adds an oxygen and leaves the typical rust stains. Non distructive testing is the only way you can know for certain. We all know that steel assemblies can look awfully bad and still be servicable and that stainless steel can look fine and be very bad.

 

[sailaway78]

Rudder leaking at post

As some may recall, I had to rebuild my rudder and replace the post last year, after some contact with a hard bottom. I was very concerned with epoxy sticking to the stainless, and called West Systems about it. They told me to lightly sand the stainless, to give it some tooth. To hopefully prevent water intrusion at the top, around the post, I sanded the stainless, and beveled the top of the rudder. Then I put a heavy bead of G Flex around the post. Does this work, I only hope so. Next time it's pulled will know for sure.
As to the rust, since it has just started, I don't think it is a major concern at this time, but keep it in mind, and a watchful eye.