How to Build Jon Boat Conversions

Preparing the Hull

• 1

  Study available Jon Boat hulls before selecting a hull for conversion. Choose between a pointed or square bow. Square bows offer more inboard room in the boat. Pointed bows move through reeds and marsh grass better than hulls with square bows. Consult with a qualified dealer to determine the best hull construction for the areas in which you plan to use your boat. Purchase the hull that meets your requirements and a trailer to haul it. Most Jon Boat dealers will offer a hull and trailer package.

• 2

  Design your conversion. Draw your plan to scale on graph paper. Measure every area of the basic hull then measure everything again to be sure your measurements are accurate. Transfer measurements to your graph paper conversion plan.

• 3

  Study your plans carefully before beginning your conversion. Jon Boat hull makers usually include two built-in bench seats as standard features. Determine how you will incorporate bench seats in your conversion.

• 4

  Measure the areas between the bench seats. Cut and fit 3/4-inch plywood into these areas to form a bottom deck for your conversion. Support the plywood with sections of 2-inch by 2-inch lumber glued and screwed to the underside of the plywood with 1-1/2-inch countersinking stainless steel screws spaced 6 inches apart. Apply screws from the plywood side. Countersink all screws. Apply a coat of marine varnish to all wood surfaces.

Installing Upper Deck and Access Panels

• 5

  Construct a removable upper deck of 3/4-inch plywood. Leave 1/4-inch on all sides of the deck to allow application of outdoor carpet as finish for the deck. Support the deck with 4 lengths of 2-inch by 2-inch lumber that span the length of the hull. Apply support lumber at each outside edge of the deck, and intermediate supports spaced not more than 24-inches. Support spacing will allow access to storage areas below the upper deck for storing fuel, boat gear, life jackets, food and beverages. Attach the supports to the underside of the deck with 1-1/2-inch countersinking stainless steel screws spaced 6 inches apart. Apply screws from the plywood side. Countersink all screws.

• 6

  Cut access panels in the upper deck. Tilt a saber saw forward on the sole plate to allow a ̶0;plunge̶1; cut through the plywood. This allows the saw to enter the plywood without drilling a hole. Repeat this method to cut all four sides of each access panel. Remove the access panels. Trim 1/4-inch from all four sides of each access panel to allow application of deck carpeting. Drill a 1-inch finger hole in each access panel for opening the panels.

• 7

  Create access panel supports. Cut sections of 2-by-4-inch lumber to support the ends and sides of the plywood removed for panel access. Position each section to provide a 1-inch ledge on all sides of the space to support the access panel. Screw each section to the underside of the plywood deck with 1-1/2-inch countersinking stainless steel screws spaced 6 inches apart. Apply a coat of marine varnish to all wood surfaces.

• 8

  Remove the upper deck from the hull. Apply outdoor carpet to the top side of the upper deck. Roll the carpet over the edges and staple at 1-inch spacing. Apply outdoor carpet to access panels in the same manner. Cut carpet from the lift hole in each panel. Replace the upper deck in the hull. Seat each access panel.

• 9

  Install seat brackets on the upper deck with 3/4-inch stainless steel screws. Helm seat should provide easy reach to outboard motor controls. Mount brackets for elevated, swivel fishing seats over the bench seats for greater strength and boat balance. Install
  Swivel seats. Mount and secure the finished conversion on your trailer ready for the water.