Mould/plug questions

Discussion in 'Boatbuilding' started by Ocboatdude, Mar 13, 2016.

  1. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    Well Ocboatdude I will not even ask about your qualifications for designing a production boat.
    Just google strip planking will you. It is a method for creating a round object out of narrow strips of wood or foam.

    But I will do you one better and explain the whole thing again because you still don't grasp it:
    1. Buy some plywood, some 2x4, screws, insulation foam, glue that works with insulation foam, epoxy resin and hardener, fiberglass, bondo, a sureform rasp, and lots of sandpaper.
    2. Build a coffin like structure out of plywood, 2x4 and screws. This coffin is the approximate size of your boat.
    3. Glue insulation foam to the exterior of the coffin.
    4. Use knives, sureform, and sandpaper to shape the foam into the final form of your desired boat.
    5. Apply fiberglass with epoxy (do not use polyester resin, it will melt the foam).
    6. Apply bondo and sand. Sand until you have a finish fit for showcar spraying and than some more.
    7. Wax and PVA according to can labels.

    Now you have your hull plug and can laminate a mold out of CSM and poly resin.

    For the deck you do the same on the coffins lid. Make plywood lid, glue foam, shape foam, epoxy fiberglass foam, bondo, sanding. To insure the deck fits your hull you take the hull plug, turn it over, put on the lid with the glued foam and shape it so that it blends with the hull. When you make the deck mold you laminate beyond the hull-deck joint so that you have a flange.

    This is the freehand method of creating a plug, fit for people who can not design and loft a boat on paper. I do not really understand why we have to explain all this to you when you say you have skills in shaping and fiberglassing surfboards. If you would want to replicate one of your surfboards you would take it, wax it and make a mold from it. The boat is just a bigger surfboard.

    However I suggest the following so that you do not spend your money chasing impossible dreams:

    1. Forget about plugs and molds for now.
    2. Learn how to design and loft your boat. This can be done on paper or with a computer.
    3. Produce detailed construction drawings for your boat. You know the kind with measurements in fractions of an inch or millimeters on them.
    4. Learn what strip planking is and construct the plug, or subcontract the plug making to a business with a big CNC to be carved out by a machine. This is to ensure your future boats match your drawings.
    5. Make molds.
    6. Build boats.
    7. Sell boats.
  2. Ocboatdude
    Joined: Mar 2016
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    Location: OC

    Ocboatdude Junior Member

    Thank you Rumars, that's what I basically needed was a step by step and that's what I was asking for. The reason I didn't understand was because no one mentioned about adding foam over the ply wood, then epoxy, then bondo.... That's why I started asking what people use as the last layer on their plug before making the mould. You broke the process down in steps and I appreciate that, it's what I really needed. Now I understand the complete process.
    Sorry if I came off as a retard but I honestly just wasn't understanding how to complete the plugs surface. And now that I know to use foam over plywood, and having skills in shaping boards the step will be easy as cake
    Again, thank you

  3. Ocboatdude
    Joined: Mar 2016
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    Location: OC

    Ocboatdude Junior Member

    Thank you for taking the time to write that out.

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