concrete

Discussion in 'Stability' started by evantica, Apr 15, 2010.

  1. evantica
    Joined: Feb 2010
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    evantica Senior Member

    I have a "space" that's gonne be hard to rust protect. I "heard" to pour some concrete there will eliminate the rust in the future???
    This concrete will be in a closed space far down in the keel section.
     
  2. Lurvio
    Joined: Jul 2009
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    Lurvio Mad scientist

    If the concrete sticks to the steel tightly and stays stuck, you might be okay. If the concrete doesn't stick or is knocked loose, you'll be in more trouble you started with.
     
  3. evantica
    Joined: Feb 2010
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    evantica Senior Member

    Lurvio, thanks! The "place" I wante to pour it in is a totally closed part of the keel! My thought was, to make the concrete so thin, and then pour it so it filled the "closed box" entiery and then seald(?) the "filling hole". Would this -in a long term -be a problematic place???
    Hakan
     
  4. Wynand N
    Joined: Oct 2004
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    Wynand N Retired Steelboatbuilder

    Keep it simple;)

    The better solution is to seal the void with plate welded to keel with threaded socket and plug fitted on filling hole. Go to any auto repair shop and get some old used oil - they would gladly give it to you free of charge just to get rid of it.
    Pour that into the void and screw close the plug. No way you will have rust from the inside after that and there are no side "effects" you may have with cement that will happens.

    BTW, I sealed all the voids in steel keels this way whilst building steel boats...
     
    1 person likes this.
  5. evantica
    Joined: Feb 2010
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    evantica Senior Member

    Great ide' wynand! thanks.
     
  6. DrCraze
    Joined: Apr 2010
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    DrCraze Junior Member

    I work with cement every day and advocate its use often, however I would advise against this. Soupy concrete shrinks considerably unless you use some serious admixtures and even then you would experience some delamination on large panels. I say fill it with tar:D
     
  7. dskira

    dskira Previous Member

    I will go with Weynand and Craze.
    I prefer personaly tar, but saw good result with oil too.
    We did the oil on life boat cavities. We did the tar on fishing boat cavities.
    So choose your poison :)
    Daniel
     
  8. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Concrete will probably let humidity through and create a lot of corrosion. Hot tar is a better product.
     
  9. jonr
    Joined: Sep 2008
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    jonr Senior Member

    I wouldn't use anything that could harden and pull away. Maybe very soft tar or very thick oil.
     
  10. capt littlelegs
    Joined: Apr 2010
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    capt littlelegs New Member

    Concrete is a traditional method of filling voids permanently and reacts well with steel, often used as repairs over rivets and welds or damage in ships. Old barges often have complete concrete bottoms in the bilge. It needs to be a proper mix rammed or vibrated in and the edges sealed later to prevent damp from getting in the thinner parts.
     
  11. apex1

    apex1 Guest

    And it needs to be removed after some years.....................

    ....which is quite a task.

    I have yet to see a vessel where the concrete did not separate from the hull causing extreme problems.

    Unfortunately 6 or 7 of my museums ships had sustained such a dumb treatment, and all needed some serious repairs on frames and plating after the cr@p was removed.

    So, I was there, have done it, got the T shirt!

    Leave concrete out of cavities.

    Regards
    Richard
     
  12. capt littlelegs
    Joined: Apr 2010
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    capt littlelegs New Member

    Not so, Dutch barges for one have used it for as long as steel has been used. You have not seen my own Dutch barge that still has the shaft set in original concrete, ninety years old and still in excellent condition. I tried to remove some concrete in the bilge, nothing wrong with it but it was so tough and attached that I would have damaged the steel in getting it out. Poor concrete or thin infills over wood may not last well but they just break up without damage, if it separates, and there's no reason why it should, then it would be easy to get out! You make up negative scaremongering stories about many things and certainly don't know everything but I'm still there, still doing it with plenty of tee shirts!
     
  13. dskira

    dskira Previous Member

    Perhaps you are right for your barge, but do not underestimate Richard, his knoweldege is deep and he do not say things just for the sake of it.
    read his posts, it is interesting and we all learn from him.
    Daniel
     
  14. capt littlelegs
    Joined: Apr 2010
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    capt littlelegs New Member

    I have seen these debates many times before, what is best depends on the particular situation but concrete is tried and proven and should not be dismissed out of hand by biased opinion.

    Sorry but I do not share your blind puppy faith in Richard, he says things for the sake of argument and reaction, if his knowledge is deep it certainly isn't wide so he adds ********, this still leaves a mess that must be discarded.
     

  15. dskira

    dskira Previous Member

    Why you insult me, are you that insecure?
    Having a friend who I like very much and is a great person, do not make me a puppy, but a human being, which you seams not gasp the principle.
    You are the ********, I try to help. Go back to your ignorance captain little *****.
    Daniel
     
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