Water in rudder

Barquito · #1 (**permalink**) 10-14-2010

I have a keel attached rudder that has a water inside. I have seen that others just drill a 1/4" hole and drain. How do I know how low to make the hole? I imagine the water gets in around the rudder shaft. Any suggestions on how to stop this leakage? or just drill out the hole every fall?

sailingdog · #2 (**permalink**) 10-14-2010

You should fix the problem. Water ingress into the rudder will lead to crevice corrosion of the rudder stock and webbing that supports the rudder if it is stainless steel. It will lead to corrosion of an aluminum rudder stock and webbing as well. Also, if you don't get all the water out of the rudder, the freezing damage caused by the water expanding as it freezes can destroy the rudder.

Barquito · #3 (**permalink**) 10-14-2010

Seems like it would be difficult to keep the rudder stock entry tight. Consider the fact that boats here experience about a 130 degree difference it temp from summer to winter (sometimes close to that daily

)

To tell the truth, I didn't get a chance to really look at the construction of the top of the rudder b/f launching this new-to-me boat. Think just dribbling some thickened epoxy into the top (after drying the inside) would work?

Bene505 · #4 (**permalink**) 10-14-2010

Drill at the lowest point to see how bad things are. From what I understand, most rudders have some water in them.

I know someone who drills every year and gets about 4 ounces of water. Um, "he" tried resealing the top of the rudder with West Systems epoxy, still had water the next year.

It means you need to get your boat on the hard before freezing temperatures hit, and get the rudder drilled. (I suppose it's possible to curtain-off the rudder and heat it somehow until the water drains out.)

I saw a boat in Maine (in January) that I liked enough to hire a surveyor (George Gallup, great guy) to survey. By the time we got there to do the survey a few weeks later, the rudder looked like burst popcorn.

Regards,
Brad

Yerffoeg · #5 (**permalink**) 10-14-2010

My rudder always collects water after a season. I have left a hole in it to drain the water out when I take the boat out of the water. If the rudder tangs are made of high quality stainless there should not be a problem. My attempts at stopping water ingress in the past using epoxy all failed.

sailingdog · #6 (**permalink**) 10-14-2010

Actually, even the highest quality stainless suffers from crevice corrosion when submersed in stagnant water, especially salt water, inside a rudder for long periods of time.

Quote:

Originally Posted by Yerffoeg

My rudder always collects water after a season. I have left a hole in it to drain the water out when I take the boat out of the water. If the rudder tangs are made of high quality stainless there should not be a problem. My attempts at stopping water ingress in the past using epoxy all failed.

Barquito · #7 (**permalink**) 10-14-2010

Quote:

Actually, even the highest quality stainless suffers from crevice corrosion when submersed in stagnant water, especially salt water, inside a rudder for long periods of time.

Would the SS hardware on the inside be more toward the top of the rudder, such that if you only had a small amound of water there would still be an air space toward the top?

Others have claimed that this is why rudders are over-engineered.

sailingdog · #8 (**permalink**) 10-14-2010

On most rudders, the rudder stock and web/tangs don't extend the full height of the rudder. Again, this will vary depending on the design of the rudder. A skeg-hung rudder may have a shorter stock than a spade rudder, which is freestanding.

hellosailor · #9 (**permalink**) 10-14-2010

There's no genteel way to really say this, but if you have ANY water in the rudder, you WILL HAVE RUDDER FAILURE. The only question is when it will fail, and how inconvenient or dangerous that may be for you.

Yes, sealing the rudder shaft isn't easy. Yes, even a casual bump at low tide can make a hairline crack that lets water in. Yes, opening a rudder up and rebuilding it is damned expensive and inconvenient.

But once water gets inside the rudder, it becomes stagnant water with zero oxygen content, and that's the perfect mechanism to cause the stainless rudder stock to fail. Unless the iron armature or frame in the rudder fails first.

You can try to drain it (takes a long time, even with multiple holes and a heat source) and then reseal it, and if you are lucky you will reseal it and the internal damage will not be enough to cause a failure. But really, there's no way to tell how safe the rudder is, or when it is going to fail. Could be this year, or 15 years from now. You're gambling once you know it has water in it.

Which is perfectly fine--as long as you KNOW that you are gambling, and what the stakes may be.

Barquito · #10 (**permalink**) 10-15-2010

Quote:

There's no genteel way to really say this, but if you have ANY water in the rudder, you WILL HAVE RUDDER FAILURE. The only question is when it will fail, and how inconvenient or dangerous that may be for you.

This is what confuses me about this problem. It seems to me that what you say is exactly what would happen. I can't imagine any steel (SS or otherwise) lasting long being in and out of stagnent water 24/7 for years. HOWEVER, as I look into this, it seems that a lot of boats have this problem. Some say even that for some kinds of boats, all of them have this problem. So, I am suprised there are not more rudder failures.