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Keel Bolts, Stainless?

Discussion in 'Thinking of buying a Moody ask a question here' started by Patrik Stintzing, 12/7/16.

  1. Hi,

    I'm in the process of buying a Moody 376. Surveying the boat I noticed that the nuts and washers of the keel bolts were rusty and the washers seems to be in need of a fairly imediate replacement. The keel bolts were affected with what appears to be surface rust. Does anyone know whether the keel bolts are made of stainless steel or only galvanised?

    I would be very grateful for any input.

    Many thanks in advance.

    Kind regards.

    Patrik Stintzing
     
  2. Dick Holness

    Dick Holness Dick Holness

    Messages:
    3,488
    Boat name:
    CANTATA
    Boat type:
    Moody 36(90s)
    Cruising area:
    East Coast France Belgium Holland
    Hello Patrick,
    All Moodys have mild steel keel bolts and washers/plates.
    It is very common to find a lot of surface rust where owners have allowed sea water to remain in the bilges. Often owners find that once this rust is cleaned off, there is plenty of metal remaining.
    For most people, it is sufficient to replace the nuts and plates. When bolts have been removed, they have almost always been found to be in perfect condition. Your surveyor should be able to tell you, however, if he thinks that the boat may be leaking around the bolts, in which case further work would obviously be needed.
    It is usual to replace bolts, if needed, with mild steel, not stainless. They are screwing into an iron keel. If water were to get in around a stainless bolt, it would cause the bolt to degrade through crevice corrosion.
    Hope this all helps. Good luck with your new boat!
     
  3. Hi Dick.

    Thank you very much for your reply. It is very much apreciated. If the deal goes through I will most likely have the nuts and washers/plates replaced by a professional yard and let them have a look at the bolts in the process. My assessment is that the bolts are only affected by surface rust so I believe that they should not constitute a large problem. With some treatment and a new coat of paint they should probably be okay for many years to come, I believe. Have you by any chance some input as to the Moody 376 as a blue water cruiser? Seems like the are used quite a lot as live aboards and for longer crossings. I would be particularly interested in knowing more about how they handles in rough conditions. English not being my first language I hope you don't mind my spelling mistakes.

    Kind regards.
     
  4. Simon Doggett

    Simon Doggett Simon Doggett

    Messages:
    441
    Boat name:
    MOODY MISS
    Boat type:
    Moody 35
    Cruising area:
    South West and France
    Hi Patrik

    Just to add to Dick's post: I understand that if you try to take off the nuts, the bolts (or studs) come out with them. You'll then need to hold the stud in a vice and unsrew the nut. All a bit tedious especially as there's a very high probability that the stud is in good condiiton. So, if you can, leave alone. Clean up the nut and plate and, unless it's badly corroded, give it an anti-rust treatment and paint of your choice.

    If you do replace the studs, you should definitely not use stainless steel.

    Simon
     
  5. Many thanks Simon. Very useful advice. What I'll probably do is to have the yard assess he condition of the nuts and plates to see weather they think they are in need of replacement. I have usualy done a lot of my repair work on my boats on my own but when it comes to such fundamental things as keel bolts, let alone working with possibly corroded material in tight confined spaces, I'll probably leave it to the proffessionals. I suppose it would be feasible to try and unscrew the nuts when the boat is up for the winter but as you say I might end up with the whole bolt coming out and I would not be sure as to how tight the nuts would have to be tightened when screwed back on.

    Thanks a lot.

    Patrik
     
  6. Simon Doggett

    Simon Doggett Simon Doggett

    Messages:
    441
    Boat name:
    MOODY MISS
    Boat type:
    Moody 35
    Cruising area:
    South West and France
    Hi Patrik

    You would need a large socket (obviously) but also a very deep one to accomodate the thread above the nut. The chap I asked to do it had to buy a new socket! You'd also need a very long bar and plenty of grunt. All in all, it would make sense to leave it to a professional. Shouldn't cost much.

    Simon
     
  7. Thanks Simon. Sound advice. I agree completely. Just waiting to have the contract finalised now and after that hopefully be able to proceed with the deal. Will definately join the Moody owners association after that. Seems like a great forum for advice, technical tips and ideas.

    Patrik
     
  8. Peter Wright

    Peter Wright Peter Wright

    Messages:
    1,219
    Boat name:
    WILD THYME
    Boat type:
    Moody 425
    Cruising area:
    North Sea, English Channel, Biscay
    Hi Patrik,

    When you join the MOA, you will have access to the work instruction for keel studs used at Marine Projects when the boats were built - this includes bolt torques and the technique they used for sealing the stud holes.

    If you or your yard intend to try removing the nuts from the studs, the result will almost certainly be that the studs come out of the keel. Before doing this it's important to ensure that the bilge is clean and dry to avoid getting water or debris into the tapped holes in the keel.

    On materials, I actually favour 316 stainless for the plates and nuts and think that the argument is finely balanced between mild steel and 316 s.s. for the studs. I don't believe a 316 s.s. nut has ever been known to fail through stress corrosion cracking (scc), even at high temperatures and the size and number of Moody keel studs results in low stress levels which are very unlikely to lead to scc at ambient temperatures, even though scc failure of 316 as studs or bolts at higher temperatures and stress levels is well known.

    Peter.
     
  9. Hi Peter.

    Thanks a million for sound advice. I will have a word with the yard and pass on your information and make sure that they take that into account. We are now sailing our Moody 376 back home to the Swedish westcoast from the eastcoast of Sweden. So far... it has been a real pleasure. I will join the MOA when I get back home again.

    Thank you once again.

    Patrik