would Stitch and Weld with metal work?

Discussion in 'Boatbuilding' started by Squidly-Diddly, Aug 20, 2022.

  1. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Like Stitch and Glue but with metal panels, more or less. Maybe instead of thick wires for temp joining use small squares of metal with holes and self tapping screws.
    Welding might have prob bridging gaps in thin metal so maybe weld a few clips on inside of hull to lock everything in place, then bridge the panels with narrow but overlapping shallow "v" strips welded to panels on both sides to create chine protrusions.
     
  2. rwatson
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    rwatson Senior Member

    What propblem exactly are you trying to solve that an spot welder or just tacking with a Mig torch or even a welding torch wouldn't solve ?
     
  3. Squidly-Diddly
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    Squidly-Diddly Senior Member

    I'm thinking it will be about 6x harder to do the temp position of metal panels VS plywood S&G for several reasons. Lower friction, thinner butte faces, and heavier weight. I guess spot welds might play a role but I'm thinking once spotted will then require breaking the weld free to fine tune repositioning VS backing out a self tapper. Plus it might take an assistant or two depending on size of metal panels and everyone would need to learn to protect their eyes from flash, etc. alumbbfig1-300x218.jpg
    All these except maybe E look like they require everything be fitted to close enough that weld bead will bridge any gaps. I'm thinking of something sorta like C where the panels would be tacked to a frame but have average of 1" gap, plus/minus 1/2". Then, on the exterior, a shallow "V" about 2" wide is placed to overlap both plates slightly, then welds are applied to exterior. Then maybe a flat (or "V" to make box?) strip is applied into interior and welded if desired. As an amateur, I can't see doing A-E correctly on my own and must be either high skill or big factory operation. But I'm pretty sure I could use my method with confidence, including creating patterns with standard CAD and "developable surfaces".

    Maybe I'd tack weld "L" clips to the panels and use hand clamps to secure to frame and adjust, especially as first step.
     
  4. rwatson
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    rwatson Senior Member

    You didn't say you were welding Aluminium alloy, which is what all those diagrams are.
    I'd say you would get better value from some accurate jigs, especially ones you could roll over as required.
    Ratchet straps, like these guys, is all you would need
     
  5. jehardiman
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    jehardiman Senior Member

    Google "origami boatbuilding"....tack then backstep.
     
  6. waikikin
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    waikikin Senior Member

    Sqiddly,

    The Van De Stadt 34 was the most "popular" for this in the 80s, it had been done plenty before but a lot of the VDS built in a short time. It was in fact 10 x easier to stitch these up, my Dad and I assembled one in a day with the plates pre cut. A simple cradle in 3 spots along the hull kept the pieces in the spot, simply a hand either side of the join was all that was required to align, some simple shelves tacked to the lower plate helped too. The stem and transom went in other days.. Quick assembly.... also known as "dress maker" as uses similar principles to form shapes.. and the "glue" dries very quickly:)
    Van de Stadt Design - Yacht Designers and Naval Architects https://stadtdesign.com/pages/assembly
    Jeff
     
  7. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Looks like it requires perfectly cut panels and some skill, and works good for 1 or 2 chine boats of limited size (runabouts).
    I'd bugger up the welds on the thin material and thus ruin the panels and end up with lots of scrap metal for smaller projects and welding practice, I'm sure of it.
    I'm trying to invent a building method that would be very forgiving and allow any size vessel and as many chines as you want. Amateur setup and secure everything with self tapping screws, then bring in a pro-welder to glue it all together, then remove self tappers and weld over those holes.
    Van De Stadt and origami boatbuilding also look like they require perfectly cut panels and some skill and know how, and a bit belong a backyard first time builder.
     
  8. comfisherman
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    comfisherman Senior Member

    Isn't stitch and glue aluminum.... rivets?
     
  9. Barry
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    Barry Senior Member

    A bit more information might help
    Is it aluminum that you are going to use? What size of boat? What thickness of material?

    Any time you have overlapping of steel or aluminum, you will more than likely have corrosion issues at the overlap sections. For steel, you will not be able to prep and paint all surfaces. For aluminum, more than likely corrosion will occur in the overlap section

    Up to about 25 feet, an aluminum build, you can build a male jig from steel and layout the sheets that you need. (larger boats are hard to turn over) It is very easy to get the joints almost light tight and then tack the sheets together on your own. There will be certain times along the build that you can hire a professional welder to make up some joints. Then continue to fit the remaining stringers, decks bulkheads etc

    If I had to build an aluminum boat from scratch at a length of over 25 feet, I would tend to buy a plasma, waterjet, or routed pre cut kit.

    You might find that this is not so much more expensive than just a set of plans. The larger companies that supply precut kits will be purchasing literally tons of aluminum which reduces their costs SIGNIFICANTLY to the point that if they do not mark the material up a lot, the net cost on the material alone may save you money. As compared to going to a retail supplier of aluminum extrusions and sheets.

    Additionally, the equipment would more than likely have a NESTING function which will optimize the material usage to reduce waste, another savings to you.

    More savings will be had in that depending on boat size, a comprehensive time and material jig may not be required.




    If you buy a plan that has patterns/drawings for bulkheads frames etc, you can make these up, tack together the jig, overlay the sheet, do your own tacking and final fitting, and hire a welder to finish

    On most welded boats, the fitting up of the sheets takes much more time than the actual welding.

    As far as thickness goes in aluminum, 1/8th is easy to Mig weld and I would recommend against Tig on full butt joints as the heat can cause distortion. Certainly there will be some who say that they can Mig down to .100, mmm?
    Fillet welds, not too much of a problem, long butt welds without backing, at .100 are much more difficult.

    So more info please
     
    Last edited: Aug 25, 2022
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  10. rwatson
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    rwatson Senior Member

    Wjat you want is Aluminium Brazing Rods. Strong enough to hold it for assembly, and can be welded over for the real deal. You just need a propane flame, and some sticks.
     
  11. Squidly-Diddly
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    Squidly-Diddly Senior Member

    lürssen ohekap ii general arragement.jpg th-1344436606.jpg
    Probably good olde steel. Something about like this, and not built to particularly high standard. About 100ft long and 20ft wide and 1---150 tons. what was wrong exactly with design of old sailing "ships"? https://www.boatdesign.net/threads/what-was-wrong-exactly-with-design-of-old-sailing-ships.67290/ Mostly a floating condo but still able to cross oceans under sail. Add big prop between the rudder and hull of course. Probably add lee-boards to both help with upwind, reduce rocking, serve as spud poles and gangplanks and ramps to the water.

    I'm thinking "V" gap bride overlap would be duplicated on the inside, maybe with flat panel and thus create a sealed chamber. Then inject some anti-corrosion paint or expanding foam.
     
  12. kdifzero
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    kdifzero Junior Member

    I just came across this 3 min timelapse of a Van S being put together very quickly but could not help notice lack of bulkhead frames and stringers, how strong would this hull even be?



    I am comparing to the recent Distant Shores build shown partly below @4:20



    and also finished @ 9:20

     

  13. jehardiman
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    jehardiman Senior Member

    Check out these two old threads...
    Steel-made hull with fiberglass-made radius chine ? https://www.boatdesign.net/threads/steel-made-hull-with-fiberglass-made-radius-chine.18224/page-4#post-153277
    Frameless steel hulls: Is there a lenght limit? https://www.boatdesign.net/threads/frameless-steel-hulls-is-there-a-lenght-limit.18528/
     
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