How to Replace a Section of a Lapstrake Board on a Wood Boat

Lapstrake construction, also called clinker-construction, is one of the oldest forms of boat building; the wooden long ships used by the Vikings were of lapstrake construction. The method begins with a keel, and internal, removable forms, rather than the conventional framework of a boat. The planks, called strakes, are then laid, overlapping each other, and glued or nailed in place. Finally, the forms are removed, so that the strakes and the keel form the hull. When you need to replace a damaged strake, the construction process is first reversed, and then the damaged strake is replaced.

Things You'll Need

  • Nail puller
  • Grease pencil
  • Jigsaw
  • Measuring tape
  • Replacement lumber
  • Adhesive marine caulk
  • Hammer
  • Brass nails
  • Marine silicone caulk
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Instructions

    • 1

      Pull the nails from the damaged plank with a nail puller. Step inside the hull and draw a line with a grease pencil along the inside of the intact strake, above the damaged strake, to indicate where the upper edge of the damaged strake makes contact with the undamaged planking.

    • 2

      Push a jigsaw down through the glued seam between the top of the damaged strake and the intact planking above it. Push the jigsaw along the seam, cutting the glue. Move the jigsaw to the seam between the damaged strake and the intact planking below it, pushing the jigsaw along the seam. Remove the damaged strake.

    • 3

      Measure the damaged strake with a measuring tape and cut a replacement, from the same type and thickness of lumber. Apply a bead of adhesive marine caulk to one long edge of each side of the replacement strake.

    • 4

      Place the board from the inside of the hull, so that the top edge of the replacement strake is inside the hull, lying along the grease pencil mark on the undamaged plank. Nail the ends of the board in place on the stem or sternpost, using a hammer and brass nails.

    • 5

      Allow the adhesive marine caulk to cure for 24 hours. When the caulk has cured, caulk the seams with marine silicone caulk. Finish the replacement strake with the desired finish.