Building the Plug

  • I started by plotting the lines in full scale. The lines were extended so that all of the station cuts could rest on a common plane.
  • I glued the line drawings to 1/8 inch plywood sheets and then cut and sanded the plywood to the lines. Each of the lines was developed to be plotted 6 1/8 inches apart. Since I had 14 sets of lines, 14 copies of the lines were needed.
  • Isosanurate foam in sheets 6 inches thick was glued to the back of each plywood cross section. Each section was then glued in series, being careful to line them up accurately.
  • The next step is to fair with saws, knives, power sanders attached to the vacuum and a longboard.
  • The foam is glassed over, sanded and faired.
  • The I put a layer of green gelcoat down and then followed with white gelcoat. This helped in the fairing operation but left the plug looking kind of ugly.
  • When the final fairing was complete the plug was polished and waxed in preparation for making the mold.