• 4th March 2007 - By greg

    Rudder plug


    stack-o-foils

    I printed out NACA0020 foil that Rick suggests using for the rudder –
    man it looks tiny, but I guess a stern hung rudder, like the typical
    ocean rowing boat is about 1/3 rd the effectiveness for a given area
    of a non-aerating position under the hull. The rudder is 12″ long x 5″
    wide by an inch thick.


    I used my micro scroll saw to cut the tight curve at the end of each airfoil because the cut needed to be squarer than my x-acto knife would cut.

    I cut twelve NACA0020 foil shapes out of 1″ thick Styrofoam and hot
    glued the stack together using a guide that to ensure that the stack
    was perfectly straight and square.

    I sanding the stack down with a sanding block and sculpted out the
    trailing edge of the rudder. I was pleased with the outcome. Then I
    spray glued about 6 layers of fiberglass fabric to it, and I’ll wait
    until the hull is out of the vacuum bag before I epoxy and bag the
    rudder.

    Then I will dissolve the foam with some gasoline, and insert my 1″ OD
    stainless tube. The rudder tube will have smaller ‘branches’ welded to
    the end where it is inserted into the hollow fiberglass rudder fin to
    grab onto the epoxy/micro mix that will I fill it up with.

    Deck Fiberglass

    Ben and Helen were my helpers today. We got messy with epoxy and
    wetted out the entire 2 layers of fiberglass roving in the Hyak deck.
    We finished in about 3 hours which must be some kind of record. I’ll
    pull it out of the vacuum bag tomorrow and start thinking about the
    drive leg well. I’m thinking of building it with Marine plywood, then
    glassing it. It needs to be super strong.

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