Welding fittings onto steel hull

Discussion in 'Metal Boat Building' started by Someofthegear, Jun 6, 2017.

  1. Someofthegear
    Joined: Jun 2017
    Posts: 11
    Likes: 1, Points: 3
    Location: UK

    Someofthegear Junior Member

    Thanks. I was planning to back step weld or just jump around all over to keep the heat down. I'm pretty slow so it'll have plenty of time to cool ;)

    I was going to cut two slots in the middle of each plate to weld to the original. Any size and shape recommended?

    I will take pics of the better welds!
     
  2. Someofthegear
    Joined: Jun 2017
    Posts: 11
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    Location: UK

    Someofthegear Junior Member

    One more question- I'm guessing I can't use dye penetrant as I can't access the back of the weld. Is there any other means to check watertightness?
     
  3. Nick.K
    Joined: May 2011
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    Location: Ireland

    Nick.K Senior Member

    Looking at your welds should be enough.

    Look carefully at the transition between the weld and plates and the weld overlaps, it should be smooth but if the weld turns in on itself you probably don't have fusion. Clean up any messy welds with the grinder, don't assume they will be alright underneath because they often won't. Grind out and redo any areas with blow holes or porosity.
    If you radius the end corners of the patches they will be easier to weld around
    At the end though if it is cleaned and epoxied that will seal up the welds well enough even if there is a bit of porosity.

    I don't know if there is a standard/ recommended way of doing that but if I was doing it I would cut the holes in the hull not in the new plate and weld them from the inside once the plate was fitted. I would probably use say a 45mm hole cutter (cut the holes before fitting the plate). Getting fusion in the bottom of a slot can be difficult, not least because you can't see the weld very well.
     
  4. Someofthegear
    Joined: Jun 2017
    Posts: 11
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    Location: UK

    Someofthegear Junior Member

    I might struggle to get the angle to weld the top of the hole from the inside, at least without taking out more of the floor. As it's under the waterline, would it look awful if I cut the holes in the new plate?

    Heating system, loo and kitchen all removed :(, trying not to find screws in the lining now. On the plus side, actually quite spacious inside now ;)
     
  5. Nick.K
    Joined: May 2011
    Posts: 328
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    Location: Ireland

    Nick.K Senior Member

    Something good anyhow!
    How do other people do this? At only 2ft wide your new plates may not need pocket welds, they are only there to add corrosion life to the hull and the strength isn't an issue; if they would be difficult to get to from inside why not put them on and see how they look without cutting more holes?

    May be doing a day trip on the Grand Union (Northampton) in the next few days:)
     

  6. Verkindgetor
    Joined: Feb 2021
    Posts: 1
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    Location: Sydney

    Verkindgetor New Member

    I also came across a bit of rust and thought it couldn't be fixed anymore but the welders from weldingnearyou.com helped me change my mind. I found there exactly what helps to cope with these problems. These welding courses opened up a new hobby for me and helped me deal with such problems and manage them on my own. This, by the way, is a good profession that helps not only you but also others, for this they pay good money, so think about it. I'm sure you'll also be interested in this
     
    Last edited: Feb 20, 2021
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