DIY Welding Gun: Plastic Repair Tool

Suppose you often feel frustrated when small plastic parts break and you do not have the right tools to weld them. At this point, you may suddenly come up with the idea of making your own welding gun. If you happen to have a small 9V transformer, you can first take it apart, remove the secondary winding, and then rewind it with 5 mm² stranded copper wire. Due to the limited space, you can only wind six turns, which gives you an output voltage of only 0.626V. You can then test the current, and the maximum peak current can reach 16.51A, while the minimum is around 7A. With this amount of current, you can meet your needs.

Once you have finished the core component, you can start building the external structure. First, you can use a piece of wood and two copper screws to make the handle. At the same time, you can use another small transformer, a small relay, four 1N4007 diodes, and a small push button to make the handle controller.

Once the whole device is assembled, you can package it to make it look neater, because a bundle of exposed components and wires would be inconvenient to carry around. If you happen to have a small metal box, you can use it as the enclosure. You can also wrap the handle with electrical tape to improve its appearance. Now, your finished product is ready.

You can test its welding performance next. You can use a U-shaped staple from a stapler as the welding tip. When you press the switch, the staple will soon begin to glow red. You can then find a broken plastic part and test it, and you will find that the welding effect is still particularly good.