Making your own pedal boat is a neat way to let you get some exercise and have a pleasurable time on the water. By repurposing an old bicycle and adding a few pieces of plywood and other simple materials, a sturdy pedal boat can be made rather easily. Then you will have a boat that you can use to get out on the water in a unique way.
Build a pair of 1- by 6-foot plywood rectangle boxes by attaching four of the 1- by 6-foot, 1/2-inch-thick plywood sheets to one another. Then insert a 1- by 6-foot rectangular piece of styrofoam into each box. Close the ends of each box by attaching a 1- by 1-foot, 1/2-inch-thick plywood sheet to each end of the boxes. Use the screwdriver bit, drill, and 1-inch galvanised screws to construct these boxes. These boxes will be the two pontoons of the boat.
Attach the 4-foot-long 2-by-4s to the two pontoons by using the drill and screwdriver bit to drive two 1/2-inch galvanised screws through the 2-by-4s and into the pontoons. Use the tape measure to place the pontoons about 3 feet apart from one another. The pontoons are now connected to one another, creating the hull of the boat.
Position two of the 3-foot-long 2-by-2s vertically on each one of the two 4-foot-long 2-by-4s. Use the tape measure to set these 3 inches apart from one another. Attach these by using the drill and screwdriver bits to drive two 1/2-inch screws diagonally at the bottom of the 3-foot-long 2-by-2s and into the 4-foot-long 2-by-4s. This places the vertical stands to support the bicycle in place on the boat hull.
Remove the front wheel from the bicycle. Then remove the back tire from the back wheel of the bicycle. Place the bicycle on the boat hull and use the screwdriver bit and drill to drive two 1/2-inch galvanised screws through the 3-foot-long 2-by-2 vertical stands and into the frame of the bicycle. This fastens the bicycle to the boat.
Attach the 2- by 1-foot, 1/2-inch-thick plywood sheet to one of the ends of the remaining 3-foot-long 2-by-2. Position the 2-by-2 at one of the foot-long ends of the 2- by 1-foot plywood sheet. Make an L shape when attaching these pieces to one another. Use the screwdriver bit and drill to drive 1-inch screws through the plywood sheet and into the 2-by-2 in order to attach them to each other. This forms the boat's rudder piece.
Place the 2-by-2 shaft of the boat's rudder piece in between the front forks of the bicycle. Attach the front forks of the bicycle to the 2-by-2 shaft by using the screwdriver bit and drill to drive two 1/2-inch screws through the forks of the bicycle and into the 2-by-2 shaft. Make sure to position the rudder to where it will sit one foot below the bottom of the pontoons of the boat. This attaches the boat's rudder to the boat. The boat is steered by turning the bicycle's handlebars in the direction that the boat operator wishes to go.
Weld the 4- by 3-inch, 1/2-inch-thick plywood pieces to the rear wheel of the bicycle using the cold welding compound. As you weld the plywood pieces into place, make sure that you use the tape measure to place them 2 inches apart from one another on the wheel. There will be a total of 13 of these paddles placed on the wheel. The boat will be powered as someone pedals the bicycle. At this point the pedal boat is finished.