grp sheet in stitch and glue

Discussion in 'Fiberglass and Composite Boat Building' started by muzungu, Jun 23, 2006.

  1. muzungu
    Joined: Jun 2006
    Posts: 3
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    Location: uganda

    muzungu New Member

    What reasons are there that I shouldn't use flat sheets of grp in a sort of stitch and glue manner? I am thinking of creating flat sheets of grp on a smooth surface (glass?), trim the edges to shape and then form them into a hull in a manner similar to ply stitch and glue, joint/fillet the corners and then glass up the interior with as many layers as I feel fit.

    Anyone any experience of doing this or any reasons why I shouldn't!

    Thanks.
     
  2. muzungu
    Joined: Jun 2006
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    Location: uganda

    muzungu New Member

    I should explain further...

    I live in Uganda and despite the country having a coastline on the second largest freshwater lake in the world, it has no modern boat building industry. Import duties prohibit me from importing a boat. I can't buy epoxy resin here, only polyester. I can't buy marine ply. I can't buy divinycel (or similar) only eps. I can't buy woven glass on csm. etc. etc. But I want a boat! and not one made out of tree trunks! You see my dilema...
     
  3. SeaSpark
    Joined: Mar 2006
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    Location: Holland

    SeaSpark -

    Sheeted poly

    I see no reason why you could not build a boat this way.

    Poly sheets are widely used in truck construction, once had the idea to build a boat with them. The sheets for trucks are to thin mostly so i would have to glue two together witch made them to expencive. This was why i dropped the idea.

    I can imagine that in a country where no marine ply is available producing poly sheets is a solution. For mass production (more than 5 ???) i think building from a mould is a better solution.

    I like the sheet making on glass idea!
     
  4. Hunter25
    Joined: Mar 2006
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    Location: Orlando

    Hunter25 Senior Member

    This is not using the material at its full potential and will result in a heavier boat. In flat panels, fiberglass does not have a lot of strength so the laminate will need be thicker. In curved, especially compound curved surfaces fiberglass comes into its own and is very strong, requiring much thinner laminate thicknesses. Flat panel fiberglass construction will have the same hull shape limitations stitch and glue plywood has. The hull panels will have to be developed. If you want to try this fine, but I would look to try a C-Flex type of build, maybe home making a C-Flex type planking and smoothing this up. You can have the nice curves, an all fiberglass boat and not have the difficulties of wood in the mixture.
     
  5. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    Many boats have been built with a wooden core and polyeater/fiberglass mat laminate over. The Stone Horse was a good example. You can build a strip plank or other method and get a lighter more efficient shape.
     
  6. muzungu
    Joined: Jun 2006
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    Location: uganda

    muzungu New Member

    Thanks...

    Thanks all for the ideas and encouragement...
    I've got a plan. I have my design sorted. I plan to make a 1:5 scale model of it using my 'pre-cast' grp sheets and test the hull form. Depending on how easy I find that to build I'll take a decision on final method of construction.

    I've approximated the cost 3 different construction materials, Steel is the cheapest but not my favorite as the construction would be completely out of my hands. Strip plank is a nice idea, timber (such as mahogany) is cheap here, albeit going against my views on sustainable sourcing (it's largely smuggled out of the Congo.) And GRP is the most costly and also very few people skilled in it's use here. Skilled metalworkers and carpenters are in abundance and cheap ($1:50 per day) so with a little instruction I can get something fairly respectable built...

    Will let you know how things go.

    Thanks again.
     

  7. skiffish
    Joined: Jul 2005
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    Location: ca

    skiffish Junior Member

    planning to do just that

    I have planned out, sheeting fiberglass and using it for panels on a stitch and glue design. The model I made worked. Just the other day I came across an article where a one off builder spoke about another doing just that. He went on to say it was westport shipyard in Washington building custom one off yachts. I plan on starting this summer trying it out on a skiff. Here is the link to article:
    http://www.boatdesign.net/articles/free-forming-fiberglass/

    Good luck
     
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