welding on a steel boat

Discussion in 'Metal Boat Building' started by sdowney717, Jun 23, 2013.

  1. sdowney717
    Joined: Nov 2010
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    Location: Newport News VA

    sdowney717 Senior Member

    Someone at marina seems to love old steel boats.
    This guy has two out of the water and is repairing the hull where it has been rusted.
    His approach is to simply weld 1/8 inch thick plate steel on top of the existing area.
    What do you think of that?
    I was thinking he should cut out the weakened areas and weld the patch.
    I am telling him that water can get into the area between the patch and inner skin and cause serious rust again. He seems unconcerned. He also says the areas have very poor access from the inside and does not plan on worrying about it.

    His welding is also looking poor, and he knows it. He had some areas professionally welded with top patches which look good on outside. Now doing patches like this also the hull is no longer smooth. Original hull was 3/16 thick.
     
  2. Wynand N
    Joined: Oct 2004
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    Location: South Africa

    Wynand N Retired Steelboatbuilder

    now you know why steel boats have bad reputations in general and moreso about rust....

    First of all, steel hulls properly built, prepared and epoxy coated will not rust or as in this case rust through the plating and 3/16ths is plenty meat in steel hull, IOW, crappy builder.
    To get the problem this far developed/deteriorated means crappy maintenance by careless owner.
    Lastly, the way the owner does the repairs as you described means he he is not fit to own a steel boat (or any boat) and should be keel hauled.
     
  3. waikikin
    Joined: Jan 2006
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    Location: Australia

    waikikin Senior Member

    In an ideal world he would cut out the affected plating with radius corners carefully fit new plating & weld out interior &backchip & weld out exterior.
    Sounds like he may have some budgetary & skill deficiencies in his ownership regime...... I agree to a degree with Wynands sentiments but if the bloke is happy in what he's doing & satisfied for his own use then steel can stand this for some extension of life, if however he then putties & lollies the boat up for sale after such efforts then that's another story.
    In my work I have the care of some vessels for static display, with these scabbed on doubler plates are quite common & usually indicated by metal thickness testing by the Surveyor who also lays out size/thickness/landing area. In essence a doubler is much like a gravo or tingle to a timber hull in it's later life.
    It's all about the application & expectations.
    Jeff.
     
  4. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Welding a patch is not necessarily bad practice. It depends on the location and the extent of it.
     
  5. sdowney717
    Joined: Nov 2010
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    Location: Newport News VA

    sdowney717 Senior Member

    In his case, patches are on forward bow area running down the keel about 7 feet on a 40 foot double masted sail boat.

    I think the boat is rather ugly, it is hard chined together using flat plates. The hull is angular, so flat plates meet other flat plates up to the true chine where side meets bottom.

    He has one small dished out thin rust spot the size of a dime in the middle under the diesel tank. Tank is integral with hull. He told me he wonders if he should weld there and says he probably will!

    He lives at the marina in a smallish fiberglass sailboat with 2 small kids.
    He always likes to talk about how strong and good steel boats are, but then I notice his steel boats are all rusty and on the hard.

    His other boat has a beautiful shaped steel hull with flowing curves. He says it is all rusty on the inside, outside looks pretty good. Has a small hole in the front which looks like a puncture. And looking at the hole, the steel feels thinner than the other boat even though they are the same length.
     
  6. Wynand N
    Joined: Oct 2004
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    Location: South Africa

    Wynand N Retired Steelboatbuilder

    You are quite right Gonzo, and so is Jeff regarding patches. Even the airline industry uses patches (doubler plates) on aircraft but according to very strict specifics and procedures.
    That said, when one go this way repairing a hull, there are some pointers and "rules" to follows, much like the airline industry to have a safe and good repair made. The way this guy does it as described by the OP does not conform to any good work practices fixing steel boat hulls. This guy is not alone in this type of repairs and in general the cause for giving steel boats a bad name.
     

  7. JSL
    Joined: Nov 2012
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    Location: Delta BC

    JSL Senior Member

    try not to waste your time on people like this.
     
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