Yes, it is possible to make a tuna harpoon at home. All you need is a piece of metal tubing or conduit, some wire, and a hacksaw. First, cut the tubing or conduit so that it is about six feet long. next, use the hacksaw to cut two notches in one end of the tubing or conduit. These notches will be used to hold the wire in place. next, use the hacksaw to cut two pieces of wire that are each about two feet long. next, use pliers to twist one end of each wire around one of the notches in the tubing or conduit. Finally, use pliers to twist the other end of each wire around your hand. Sixth,