1945 Steel deck to teak join rusting

Discussion in 'Boatbuilding' started by chrisa, May 8, 2019.

  1. chrisa
    Joined: May 2019
    Posts: 2
    Likes: 0, Points: 1
    Location: UK

    chrisa New Member

    Hello,

    I have purchased a steel boat that has been much loved by the previous owner, there is however one big problem.

    The deck is leaking, it's steel with a raised teak section which has been laid over steel stringers supporting the deck and coachroof. I can see the teak deck from inside the cabin.

    The issue is that the steel rim has began to seriously rust and swell and water now gets between teak and steel, additionally the steel on the deck is getting thin in some places on the deck.

    I can not think of a way to easily repair it by replacing it with fibreglass, as there has to be a point where the glass joins the steel and this will not look pretty. I am reluctant to go down the steel route as ... well it's a lot more work (I can do the FG work myself), but I see it as the only option.

    I have attached a diagram and photo's, any suggestions would be much appreciated.
     

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  2. Nick.K
    Joined: May 2011
    Posts: 327
    Likes: 21, Points: 18, Legacy Rep: 103
    Location: Ireland

    Nick.K Senior Member

    It's a lovely looking boat, a lot of the charm is in the swept deck .

    I don't think there is any easy fix. Rust scale expands and is porous so the teak deck strakes will be being pushed away from the underlying steel and will be more or less impossible to seal without removing the rust which will entail removing the timber deck. Fibreglass or a coating applied over the top will be unlikely to work for the same reason. Water will end up entering from the edges.
    If the steel deck structure is very pitted under the timber then it will be necessary to blast clean it if you are going to stop the corrosion long-term. You will probably also find that the hull is corroded inside where water will have been leaking in.

    My first thought was that if the boat was mine, I'd use her on fine weather and have a deck tent made to shed the rain when not in use.
    Second, I was thinking if it may be possible to remove just the outer strakes on the deck to the edge of the steel plate which could then be cleaned with a needle scaler, epoxy treated and the strakes replaced re-bedded on the epoxy. Blasting would be more effective but it would fill the interior with grit.
    For a long term solution if it was mine I'd remove the timber, plate the deck in steel and lay a cork overlay on top to mimic the original teak pattern.
     
  3. chrisa
    Joined: May 2019
    Posts: 2
    Likes: 0, Points: 1
    Location: UK

    chrisa New Member

    Hello,

    Appreciate your response, the inside is dry except for the rear where the bilge is wet and I can't easily access the area under the engine.

    Either way there is a lot of work that needs to be done and replacing the steel on the deck appears the be the best approach.

    Thank you for your insights!
     
  4. JamesG123
    Joined: Mar 2015
    Posts: 655
    Likes: 75, Points: 28, Legacy Rep: 10
    Location: Columbus, GA

    JamesG123 Senior Member

    I hate to say it but also take a good look behind the ceilings (walls) and fittings inside the cabin. if you are getting corrosion around the gunwales and its leaking, you might be getting it down the insides of the hull too. Rust and rot are like cockroaches. If you see one, there are always more. Best of luck.
     

  5. Nick.K
    Joined: May 2011
    Posts: 327
    Likes: 21, Points: 18, Legacy Rep: 103
    Location: Ireland

    Nick.K Senior Member

    It may not be necessary to replace it. Most likely if it isn't actually perforated already you could get away with just cleaning it. If there are a few areas where it is paper thin then those could be individually cut out and replaced. To replace everything would be a large job, not so much in the steel work as trying to keep the interior in good condition, assuming there is an attractive interior to match the outside.

    Before launching in to a major job it would be a good idea to expose some of the under-deck and upper hull sides to assess if there is corrosion inside as well.

    How thick are the deck strakes? Are there any leaks through the deck or is the problem area just limited to the timber/steel joint?
    If the issue is limited to the timber to steel deck joint and the teak strakes are thick enough then it may be possible to carefully remove just the outer strakes exposing the corroded steel. The steel could be cleaned with a needle gun while using a powerful vacuum cleaner to suck off most of the dust. A good steel epoxy paint such as Jotamastic or Hempadur would protect the steel for many years to come and new bedding under the strakes would prevent leaks at the edges.
     
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