rusty keel bolts....

[yourmomm]

this may seem like a stupid question (evidently i am accused of asking such...), but the exposed part of the keel bolts of my boat (replaced as new in 1996) seem rusty as hell to me-no paint on them whatsoever and not apparently electrically bonded either. pulling them looks a nightmare. and x-raying i hear is super-expensive (not that i know anywhere i can have this done). they are 22mm diameter. anyone know of the usual lifespan of such things....? if around 10 years i'd better get working.....any hints on pulling greatly received. many thanks

 

[tillergirl]

If you do a search, you will pick up some old threads on this including my own experience in removing and changing the bolts two winters ago. If they weren't painted in 1996 then they wouldn't look good. What's the condition of the keel/hull joint. My experience was that where I had serious/bad rust weeps at the joint (externally) then I had trouble with the condition of the bolt.

I think Mirelle who posts here removes his every ten years which is a good idea. They can be still relatively easy to move after that time. The cost of a mild steel bolt isn't great so generally if I have mine out I replace them. Others, of course, have more noble (and expensive) metals.

I think I would be looking at the condition of the nuts and tops of the bolts in the bilge. Are they clean, rust free, free of any water seepage? What does the keel/hull joint look like. No signs of rust? Wire brush the bolt heads in the bottom of the keel. Do they all look sound when clean and well bedded? If all that looks positive, then you have to ask yourself, 'do I want to follow a sensible maintenance regime like Mirelle? (With apologies to Mirelle if I have misquoted him!). I have eight years to make my own mind up.

You don't say what boat - age.

 

[yourmomm]

thanks tillergirl-the boat is built 1970. bolts were never painted but having said that, there are no rust streaks on the keel/hull join, (just everywhere else /forums/images/graemlins/frown.gif) and no unusual movement in this join either. but this is not the sort of thing to take a chance with i guess, so mirelle may be right....ANOTHER job to chalk up for the winter, perhaps....

 

[oldfrank]

The condition of your keel bolts will to some extent depend on their material. I am aware of an unscrupulous yard who fitted new yachts with mild steel keel bolts - they needed replacing after a year. Rust is a little like blood - a little goes a long way and what looks awfully bad may be either a minor wound or keel bolts that are quite serviceable.

About five years ago I replaced the entire rig on my prewar Broads sailing boat (freshwater). The boat had been built in 1939, using a keel from a boat originally built in 1937.

There was some rust leeching from the keel and I had a sneaking feeling that I might look a considerable prat if the keel fell off and I lost the new rig. Maybe I should add that the sitka spruce alone for the 50' mast cost £2,500 then.

We dropped the keel, inevitably found another job or two and replaced the old wrought iron keel bolts with 1" stainless. The old keel bolts were destroyed during removal but they turned out to be fine. We sailed on with more confidence in a blow but it just goes to show - you never can tell. OF

 

[cliffordpope]

I can't believe anyone would seriously use mild steel. The proper material is wrought iron if bolting on an iron keel, or bronze (eg silicon) if a lead keel. It is always said that stainless steel must not be used underwater, I'm not sure why.

 

[oldharry]

[ QUOTE ]
It is always said that stainless steel must not be used underwater, I'm not sure why.

[/ QUOTE ] Stainles steel forms an oxidised coat in contact with oxygen, which prevents it from corroding further. Below water it 'drowns' and can corrode very rapidly. This takes the form of pits and crevices which eat rapidly into the metal and weaken it. Crevice corrosion can rapidly go quite deep into the material.

 

[Mirelle]

Agree with TG

To be precise, I knock one bolt out for inspection every ten or twelve years or so (roughly).

In point of fact I have renewed the lot each time, except for the one under the engine which is "out of sync" as it gets done if the engine comes out!

Used mild steel in 1980's, wrought iron in 2002.

If you have no rust weeps, you don't have a leak.