Question about Moulds

Discussion in 'Boat Design' started by pironiero, Aug 21, 2021.

  1. pironiero
    Joined: Apr 2020
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    pironiero Senior Member

    So ive stumbled upon LA28 building process and they are making their hulls a little bit different from the rest, they using two half moulds and then glue them together lenght wise
    Like that [​IMG]
    The question is-what are the benefits of forming a hull this way and also drawbacks?
     
  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Although the mold is made up of two symmetrical half-molds, the hull comes out in one piece and there is no need to glue anything. The two half molds are joined by screws and greatly facilitate demoulding.
    The double half-mold also allows, by adding some pieces, slight variations in the overall beam of the boat and in its general configuration.
     
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  3. wet feet
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    wet feet Senior Member

    The majority of boats are made in two piece moulds.that way you can have a bonding flange for the deck moulding to sit on that guarantees a consistent height for all boats.Not all moulds are split on the centreline as some have a removable top section and still others have a removable transom if there is a retrousse transom.One further advantage of a centreline split is that the laminating platform is easier to access for much of the build and then when the time comes to release the hull,it is easier to wheel the mould sections away than to lift the hull over the top edge of the mould.
     
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  4. kapnD
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    kapnD Senior Member

    A split mold allows convex features like a tumble home and reverse transom to be allowed, and even decking as part of hull laminate.
    When laminated in two halves, it opens up a new dimension in interior molds, where hull sections can be closed over full modular interior units.
     
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  5. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Morgan Yachts was building hulls in two pieces back in the early 70's.
     
  6. Mr Efficiency
    Joined: Oct 2010
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    Mr Efficiency Senior Member

    Isn't he saying the boat itself is "split", not a boat made in a split mould ?
     
  7. mudsailor
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    mudsailor Junior Member

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  8. Mr Efficiency
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    Mr Efficiency Senior Member

    I did Google it looking for a glass version, saw reference to cold moulded veneer construction and assumed that wasn't what he was alluding to.
     
  9. bajansailor
    Joined: Oct 2007
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    bajansailor Marine Surveyor

    That LA 28 is just gorgeous - but gorgeous always comes at a price. 120,000 euros (ex VAT) for a 28' day sailer with some basic accommodation.
     
  10. wet feet
    Joined: Nov 2004
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    wet feet Senior Member

    I did the same and reached the erroneous conclusion that the boat shown was a prototype-aided by the illustration in post #1 showing a white deck edge.As for cost,I expect a large amount of it can be attributed to the time and effort required to achieve a good finish inside and out.The rig and fittings would cost just as much for a hull of any material.I doubt the builders will be pondering the options list for a new Learjet in any case.
     

  11. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Morgan made the hull in two pieces and then laminated them together.
     
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