Rust dripping from keel joint.. Should I be worried ?

[boden36]

I am very surprised to see rust presenting like this on an underwater surface.
How long has the boat been out of the water?
Underwater, with the correct number of anodes there should be no problem.
As it is now I would strip out the area to bare iron, treat and re seal.
The only thing that would worry me would be if there was evidence of significant corrosion between the keel and the hull, ie. inside the joint.

Regards,
Richard

[Sandero]

So you see rust on a steel hull and you decide to remove and inspect every bolt and look for crevice corrosion...

[Flyingriki]

Yawn.......

[boden36]

Sandero, its not like that at all. I have built , owned and maintained a steel yacht for 30 years. At the moment there are areas of paint missing below water. No rust. You don't get rust underwater. It needs oxygen.
If I find rust above water, I sure do investigate and remedy it, even the smallest bit.
Rust in a crevice is particularly worrying as rust expands and can force materials apart.
It is far better to spend a little time checking things and remedying them if necessary. That way the weather and seas can be crappy as hell and the last thing we need to worry about is the integrity of the boat.

Regards,
Richard.

[Sandero]

Originally Posted by boden36

Sandero, its not like that at all. I have built , owned and maintained a steel yacht for 30 years. At the moment there are areas of paint missing below water. No rust. You don't get rust underwater. It needs oxygen.
If I find rust above water, I sure do investigate and remedy it, even the smallest bit.
Rust in a crevice is particularly worrying as rust expands and can force materials apart.
It is far better to spend a little time checking things and remedying them if necessary. That way the weather and seas can be crappy as hell and the last thing we need to worry about is the integrity of the boat.

Regards,
Richard.

This is not a steel boat... it a cored glass boat with an attached flanged iron keel.

[Pete7]

Originally Posted by boden36

I am very surprised to see rust presenting like this on an underwater surface.
How long has the boat been out of the water?
Underwater, with the correct number of anodes there should be no problem.
As it is now I would strip out the area to bare iron, treat and re seal.
The only thing that would worry me would be if there was evidence of significant corrosion between the keel and the hull, ie. inside the joint.

Regards,
Richard

Richard, what will you do the following year when the other side shows rust and it will. I have two keels and its a bit like painting a bridge, a never ending story. The best I can achieve is to clean off the rust, treat it, slap some paint on and fill the gap with sikaflex then antifoul over the top. That will work for a couple of years then repeat. However, its not a problem because that keel is going to last much longer than me or the rest of the fibreglass yacht.

Pete

[minaret]

Originally Posted by Sandero

Absolutely... I have similar experience and I discussed this issue with Dick Zaal the architect of my Contest. Mr Boatpicker is being alarmist and has no experience with this boat and how their keels are attached.... a technique they have been using for more than 55 years with no keels dropping off... since Mr Boatpicker was a youngster or maybe not even born.

This is not an uncommon construction method by any means, though it is most certainly an inferior one. I'm quite certain that any surveyor with a fraction of poker's experience has surveyed any number of vessels with identical construction. There is nothing special about this construction method. The OP should consider listening to the pro. Glassing over keel bolts is a terrible practice, as it creates the perfect conditions for crevice corrosion. Many times I have taken such an install apart and found severe corrosion in only one or two bolts with the rest OK. Only one way to know for sure, drop the keel and inspect the bolts. Telling the guy his boat is fine based on anything less is very very unwise, to say the least.


To the OP-that's a lot of rust. Grind off the glass over the bolts, drop the keel and inspect everything, then put it back together. This is basic maintenance for any boat over twenty years with unknown condition of keel bolts. Only way to know for sure. Short of this, don't cross any oceans or go too far from help. JMHO!

[boden36]

Pete,

I would do what you do - the main thing is to keep an eye on it and keep it under control. I would be concerned about a build up of the products of corrosion between the keel and the fiberglass which may distort and ultimately damage the fiberglass.

Regard,
Richard.
.

[Captsteve53]

Obviously a heated topicand may as well step back in the fray and get abused as well(Im also a marine Surveyor Lloyd's Certified and current member of IIMS) Certified class 1 Marine Engineer of 30 years, My input

1) For the input of "no rust under water because of no oxygen" is completely false -there's actually more oxygen in sea water (depending on temp and depth) than in the air @ (20%)
2) Regarding the statements re cast iron and the rusting as a whole compared to the keel bolts is also erroneous and again shows the writers lack of knowledge regarding metallurgy,
3) Cast iron actually can be better in regards to corrosion than steel, not to mention many of these keel bolts are galvanized(Jeanneau) and act as a sacrificial anode and eat away way quicker than the cast iron keel
4) Encapsulated BOLTS under GRP still corrode and is in my opinion only a bad practice,
5) I also note the worst abuse seems to come from un qualified persons who seem to think sailing for 30 years makes them capable of professional input where life could be at stake (Recent keel bolt failures causing death) so if the professionals err on the side safety at least they are being cautious based on fact,
6) below pictures show keel bolts under GRP and the wasting of keel bolts where the heads nearly caused loss of keel, the photo of the keel bolt was the best of ten/Note the bolt is fine but the head was ready to pull through the keel,
7)This keel had similar exterior issues showing as this thread and the diligent owner was not happy with the yards advice(it's normal -dont worry)

I offer the forgoing only as advice with no preconception, with no legal implications and without prejudice.

Cheers Steve