If you want to build your own fishing boat, you can use your weed trimmer to build an outboard motor. The process is simple for those who have experience with welding and metalworking. The materials are simple, and the product is both economical and efficient on simple one-man boats.
Take the weed trimmer apart by removing the nuts, bolts and screws. Take the motor out.
Weld the one aluminium rod straight on the extending rod from the weed trimmer. Make sure that it is straight.
Weld the propeller to the bottom of the rod, making sure that it is facing out and perpendicular to the rod.
Bend the other aluminium rod around 1/3 the way down by 45 degrees with your hammer, and weld the longer end about 2 to 4 inches from the propeller. This is tiller, which controls the boat.
Drill a hole where you bent the second pole, and tie one end of your rope through the hole. Tie the other end onto your motor. Mount motor to your boat.
Double the amount of welding wire you apply so that your motor will last longer.
Allow adequate space for welding.