How to Build a Rudder and Skeg

Rudders are foil-shaped to reduce drag and to create lift. The sleekness of the skeg also reduces drag in the water. Because they hang low beneath the boat, the rudder and skeg are likely to get damaged in the event of a grounding. Scrapes to these two parts from launches, beaching and other contacts wear away protective coatings, making the parts susceptible to rot. You can build a new rudder and skeg by using the worn parts as models for their replacements.

Things You'll Need

  • Boards - slightly thicker than the old rudder and skeg, at least 4 inches wider and longer
  • Pencil or marker
  • Electric drill and a 17/32-inch drill bit
  • Electric hand-held jigsaw
  • 1/2-inch dowels
  • Marine glue
  • Hammer
  • Clamp, vise or helper
  • Damp rag
  • Hand-held plane
  • Belt sander with 40-grit sanding belt
  • Assorted grit sandpaper sheets
  • Razor knife
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Instructions

  1. Making a Rudder

    • 1

      Lay the boards on a worktable in the form of a rectangle.

    • 2

      Mark the boards to locate dowel holes to be drilled into the side of each board where the boards meet. The holes must align to make a dowel joint.

    • 3

      Use the drill and a 17/32-inch drill bit to make matching holes in the sides of the boards where they meet, 1/2-inch in from both ends. Make the holes 3 1/8-inches deep. Be sure the holes are in alignment. Make additional holes up and down the sides, 5 or 6 inches apart.

    • 4

      Use the jig saw to cut the dowels into 6-inch pieces. Put marine glue into the holes of the first board. Use the hammer to drive the dowels all the way down into the holes on the side of the board.

    • 5

      Turn the board on end with the dowels protruding upward. Secure it with a vise or clamp or have your helper hold it on end. Put marine glue on the edge of the board. Place the second board on the dowels and drive the board down onto the first board. Work up and down the edge of the board, gradually bringing the two boards together tightly. Remove excess glue with a damp rag. If there are other boards, repeat until all are joined in the same manner. This is your rudder blank.

    Shaping the Rudder

    • 6

      Lay the rudder blank flat on the work table. Lay the old rudder or rudder plan on top of the rudder blank. Move it around until it fits inside the rudder blank completely.

    • 7

      Use a marker or pencil to trace the outline of the rudder onto the rudder blank. If you used plans, use the needle-point pattern tracer to trace the outline of the rudder, and then darken the outline with a pencil or marker.

    • 8

      Use the electric handheld jigsaw to cut out the outline of the rudder.

    • 9

      Use the pencil or marker to mark the top and bottom end grains with the shape of the rudder foil. Use the hand plane to cut the board into the rough shape of the foil.

    • 10

      Use the belt sander to refine the shape of the foil. Use the razor knife to cut the assorted sandpaper sheets into smaller strips that easily fit into your hand. Finish off the foil shape by hand sanding with progressively finer grit sandpaper until you are satisfied with the shape of the rudder.

    Making the Skeg

    • 11

      Join the boards using a dowel joint. Follow the same procedure that you used to join the boards for the rudder.

    • 12

      Use the handheld electric jigsaw to cut the boards for the skeg blank. Follow the procedure that you used for the rudder.

    • 13

      Use the plane, belt sander and hand sandpaper strips to shape the skeg.