Bleeding keel

[seafox]

Last time the boat was hauled I noticed that about a half metre down the keel there were some blisters with some water in them. They were leaching a green coloured water substance sort of like brass corrosion.

The blisters are the same distance apart that the keel bolts are.

The top of the keel bolts inside the boat are fine. No corrosion, dry and no sign of any problems.

The keel is a fin keel and I draw about 1.8m. It is glass for maybe a foot and then the lead starts.

I have a few questions:

When the keel is formed do the bottom of the keel bolt shafts get put into the molten lead?

If not, how are they attached at the bottom to the lead?

Next time the boat is out should I take the grinder to the side of the keel and start exploring to see what is going on? I can easy epoxy it all back up. After it is expoxied I can sand and antifoul it and it would look no worse for wear.

What do you reckon is going on? It has actually been doing this for four years now and probably a lot longer for the previous owner.

cheers

[swagman]

Hi Matey,
I'd be suprised if the top half of the keel was just glass.
Normally a lead keel is cast over a steel web - and the 'flange' on the top of the keel is steel. Normally the keel bolts are either tapped down ito the top of that steel - or the bolts secured each end with nuts inside the boat - and locked nuts in voids in the web.
Its not unusual for the top half of a keel to be glass covered and any 'voids' in the web filled. Its equally not unusual for a hard grounding to maybe break the keel / hull seal and for water to get into the top of a keel web - possibly rusting internally.
Such rust - expanding - could well be the blisters.
The colour of water leaking from them could be down to anything - but be careful in the way you cut back to expose whats wrong and sort out the issues. Most keel makers once it is cast, will laquer the steel with some pretty longlasting coating to prevent such future rusting. You don't really want to harm such a coating when cutting your way in.......it might just be keel nuts / washers rusting....might justbe some viod bog breaking down etc.

So speak with the builders (if you can) - find out exactly how the keel was fabricated - and aim to go at it slowly.

Take care
JOHN

[GordMay]

The "... glass for maybe a foot, and then the lead starts ..."
is probably referring to a bilge sump, keel mounting stub.

[Alan Wheeler]

If this helps anyone, it's a Lotus 10.6. Sorry if I got the last number wrong Darryl. I am out of my depth on this one, so won't offer any advice. Apart from, sometimes the "green" colour can infact be from the resin. The moisture can become very acidic inside, which is what causes Osmosis, and the water can change colour. Now in saying that, I am not saying you have Osmosis in the hull, it is more likely something else that has started this to have it in the specific points around the Keel. But the actuall blisters will be Osmosis caused. What has caused that I dunno.

[seafox]

Thanks.
The hull is fine. It is just the small blisters down the keel on both sides. Kind of telling me that something is up. Each time I antifoul I just paint over them and put the boat back in.
I will have a talk to some boat builders next time it is out.

[SkiprJohn]

Aloha Seafox,
I'd grind them back the next time you haul out and see what's up. As you say it's easy enough to just epoxy patch up a hole and it will give you a great deal of piece of mind. If it is just osmosis then as soon as you haul pop them and grind them out. Do the repair on them last thing before splash because you want max time for them to dry out.
Kind Regards,
JohnL

[delmarrey]

A couple questions???

What Material are the keel bolts??

Are you sure the keel is lead?

I suspect that some copper based material is leaching out threw cracks in the keel. Maybe someone used a copper based material for the ballast. Fiberglass usually does not extend over a lead keel very far, if at all.

These are a guess but I think I'd do a little exploritory surgery like mentioned above........................._/)

[seafox]

The keel bolts look to be bronze. Pretty sure the keel is lead. Had a scuff at the bottom and at one stage and it certainly looked like lead. Will do the grinder thing next time it is out just to see what's a happening.

[seafox]

I will take some photos to put on here as well. Wont be till next season though. It was just good to start asking now.

[Latitude9.5]

My keel has glass running beyond the portion where the stub bolts to the lead, it cracked as well over the years from stress, when i hauled it (actually still on the hard thanks to a no show for my stuffing box) I ground the crack out and filled it so water would not continue to rust away. We'll see how it holds

[Alan Wheeler]

Awwe c'mon Darryl. Just get Paula to lean over the side and snap a few when you next go over the bar in a good N'wester.

[seafox]

Awwe c'mon Darryl. Just get Paula to lean over the side and snap a few when you next go over the bar in a good N'wester.

Now there's an idea!

My keel has glass running beyond the portion where the stub bolts to the lead, it cracked as well over the years from stress, when i hauled it (actually still on the hard thanks to a no show for my stuffing box) I ground the crack out and filled it so water would not continue to rust away. We'll see how it holds

Yeah I can see where the lead starts too. There is a line that stands out where the lead starts. It looks like I have bolts down to that line then lead from there on. The whole keel is encased in Fibreglass though.

[delmarrey]

Last time the boat was hauled I noticed that about a half metre down the keel there were some blisters with some water in them. They were leaching a green coloured water substance sort of like brass corrosion.

The blisters are the same distance apart that the keel bolts are.

With bronze keels bolts I would say the that salt has gotten into them and that's what is bleeding the green.

Originally Posted by latitude9.5

My keel has glass running beyond the portion where the stub bolts to the lead, it cracked as well over the years from stress, when i hauled it (actually still on the hard thanks to a no show for my stuffing box) I ground the crack out and filled it so water would not continue to rust away. We'll see how it holds

I'm not sure I'd want to be sailing around with a cracked keel. You all know what happens when they fall off

[Alan Wheeler]

You all know what happens when they fall off

Ummm, they turn into a power boat???????

[seafox]

With bronze keels bolts I would say the that salt has gotten into them and that's what is bleeding the green.

I think so too. When the boat has been out the water for a few days the stain is like a bronze/copper stain around the area. I will do some exploring next time it is out. The bolts should be ok though. Bronze props are in the water all the time and bronze seacocks and dont disolve too quick