Best, Easiest method for amateur built plug?

Discussion in 'Boat Design' started by James Mills, Mar 7, 2008.

  1. James Mills
    Joined: Jul 2004
    Posts: 29
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    Location: Bradenton, FL

    James Mills Junior Member

    What is the easiest method to build a plug?? -- for an amateur with some skills. I hate sanding and fairing but could tolerate it on a soft substrate to make the plug.

    Thinking a plug / mold for the bottom of the boat or perhaps the front 1/3 of the bottom and some of the topsides then the rest out of composite panels created on a mold board.

    Amateur effort trying to create a professional result.

    Thanks in advance for the wisdom of the Forum's experience.

  2. tinhorn
    Joined: Jan 2008
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    Location: Massachusetts South Shore.

    tinhorn Senior Member

    An old fiberglass how-to book showed how to build plugs from plaster of paris. I've carved/sanded two-pound urethane foam into plugs, slathered them with gelcoat (you have to be gentle with the sanding), and then made a mold. And yup, I've used pieces of fiberglass as part of my plugs, too.
  3. Gashmore
    Joined: Feb 2008
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    Location: Macon, GA

    Gashmore Junior Member

    You can build a plug out of almost anything. Door skin strips over station frames is common for larger hulls. Foam blocks are good for smaller ones. (Not Styrofoam) It just has to be strong enough to support the mold without distorting but the surface has to be perfect. The plug/mold route is an awful lot of extra money and work for a one off. The thing is when you finish the plug you are only 1/3 of the way. With just a little more effort you could build the actual hull.

    I have built several molds for things like shower pans, grey water sump, refrigerator lids, pedestal and instrument pod.
    I used everything from scrap wood to 4 lb poured urethane. I spray my plugs with 3 or 4 coats of Duratec surfacing primer. Wet sand to 600 and compound with 3M Perfect-it followed by 3 coats of carnauba wax and 3 coats of PVA.
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