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

[Mat86]

I noticed some rust dripping from the keel joint, when the boat was on the hard recently.. Is this a normal thing ?
It's a Contest 38s with a wing iron keel.

Any thoughts are much appreciated

https://youtu.be/JCk77-FCbVE
(excuse my bad video)

[model 10]

I don't know about worried but I would be looking at some work ahead. You will need to remove all that old fairing compound, check the bolts and re-fair the whole thing.

[Sandero]

Probably not... I also have a Contest but with a fin keel.

The design of the keel to hull is such that the cast iron keel has a 1" or so flange integral to the keel casting which about 12- 15" wide if I recall correctly. The bolts are spaced about 10 apart athwarship so this gives the keel an wide end plate and it's very strong.

The the hull has a recess molded into it to accept the keel flange. The hull at that point is about 3" thick of fiberglass! As you know the keel bolts are glassed over and not exposed.

When the keel was installed Conyplex bedded it with some sort of sealant / caulking...

THERE IS SOME MOVEMENT in all keels when the boat heets... no matter how small it is. The wide end plate flange greatly reduces this movement.

Then the whole recesses is filled with fairing compound... and this is what will ALWAYS crack a bit even if glass tape is used over the joint.... the tiny crack allows water egress and promotes the rust you see. This is surface rust from the iron keel... it is not a concern. If the keel were lead you would see a crack but no rust.

This is one of the most robust installation of a keel I have seen. If it's any comfort to you, I have the same stuff and have owned the boat from new 32 years ago and sailed it 40,000+ miles and a fair amount of that offshore.

Don't be concerned.

Now you see it... now you don't.

[Sandero]

Originally Posted by Guy

I don't know about worried but I would be looking at some work ahead. You will need to remove all that old fairing compound, check the bolts and re-fair the whole thing.

No you don't have to check the bolts.... they are bolts from above and it's glassed over.

He can remove all the fairing.... sandblast the flange... coat it all with underwater epoxy and then fair it all.... and in several years it will happen again.

[sharkbait007]

We have a 42' Conyplex Contest and seen a similar thing during our last haul out. After removing much of the fairing compound as mentioned, I found the same wide keel flange and had small amounts of rust weeping out of the seam where the flange meets the fiberglass. It dried out a few days in the heat after exposure. A very solid built boat. I wouldn't fret over it.

[Mat86]

Thank you all so much for your reply's. I can say how much more helpfull your replies are, compared to 'professionals' around here

Happy sailing

[Pete7]

Fairly standard problem with iron keels. We put some sticky stuff in the gap and paint over the top with antifoul paint each spring, then go sailing

[Captsteve53]

Couple of questions to ask your self and observations just before you go off thinking it's all great then some thing tragic occurs especially due to the recent high public situation with keel failures,

1) How old is the vessel?
2) Is water still dripping/leaking (how long did it drip if now stopped?)
3) Carefully check for any small cracks around the joint line both out side and inside
4)Are there any signs inside that the bolts have moved(GRP cracks where covered over?
5) You may have to remove some floor boards or the more permanent sole boards to inspect
6) Do all the removable floor boards still come up easily?
7) Do you get un explained water in the bilge?

Yes most external keels will move slightly and quite possibly have a hairline crack with as in your case rust from the cast keel but you need to evaluate the above first, The movement or lack of goes back to the flange area and system used and type of sealant used (5200 is a good keel "Glue" ) and dont see to many failures when this is used,

The issue being you dont really know where the rust is coming from probably the keel but who knows-vessel age is prudent here! and having the keel bolts encapsulated dosent help if the water is seeping in from the keel to hull joint,

I recently removed a Jeanneau keel (Cast) for the same reason now the nuts on the top under the GRP where all good except 2 , but the real issue was the head of the bolt (countersunk type located out side the hull in the keel) every one was wasted by 70 -90% and probably would have pulled through the keel easily in heavy weather or grounding /striking a submerged object,

I can find the pictures and post if you desire to scare your self!

All that said I'm not trying to do that at all and some other posts are quite probably correct in there assessment, BUT as I do this for a living I prefer to err on the side of caution in these possible life threatening situations - in the last keel falling episode where the owner new of possible keel issues caused loss of life and now being charged with criminal intent. Just be prudent!!!

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

Cheers Steve (IIMS Surveyor/ Lloyd's accredited)

[silverbeard1]

Let us know when the Keel falls off Oh I hope you will be around to tell us

[roland stockham]

Despite other advice I would say you do need to be concerned. On a fin keel stresses can be high on the keel bolts. At some point I would want to examine a keel bolt or find another way to check that water has not penetrated that far. It probably hasn't but I would want that to be a definitely hasn't before sealing it up and possibly sealing in structural corrosion.

[Sandero]

Originally Posted by roland stockham

Despite other advice I would say you do need to be concerned. On a fin keel stresses can be high on the keel bolts. At some point I would want to examine a keel bolt or find another way to check that water has not penetrated that far. It probably hasn't but I would want that to be a definitely hasn't before sealing it up and possibly sealing in structural corrosion.

Ronald.... sure the rust could have a structural implication....

However... considering the way Contest attaches its iron keel this is less a consideration than in typical attacked keels

my keel is 6,500# including a 14" w x 120 long flange with 16 keel bolts.

Presumably each bolt is carrying ~400#... Do you expect some rust to serious compromise the strength? They have with a minimum tensile strength of 120,000 PSI // area of each bolt is .8 sq inches or has a tensile strength of 100,000 pounds.

[boatpoker]

Two pictures are worth ......

[Sandero]

pics can be deceiving.... need to know more.

[boatpoker]

Originally Posted by Sandero

pics can be deceiving.... need to know more.

Simply that you don't get corrosion staining without corrosion and you need to investigate further. New fairing compound covers it but does not solves it.

[Sandero]

Originally Posted by boatpoker

Simply that you don't get corrosion staining without corrosion and you need to investigate further. New fairing compound covers it but does not solves it.

He has an entire keel made of cast iron... and you think it's only the bolts? If he had that sort of corrosion he could observe his keel flaking off.

Be logical.

Ah you're a surveyor... that explains it. Have you surveyed any Contest Yachts? Have you looked at their keel bolts?