Here is a step-by-step tutorial on how to make an 800 amp Spot Welder from common materials and for dirt cheap! Spot welders are used to fuse thin sheets of metal together and can cost hundreds of dollars to buy. In this video, we’ll do it for practically nothing!
WARNING: Burning galvanized metal may release toxic Zinc Oxide fumes. This project is extremely dangerous and should not be attempted without adult supervision and adequate training. Misuse, or careless use, of tools or projects may result in severe electric shock, cardiac arrest, serious injury, permanent damage to equipment and property, and/or death. Use of this video content is at your own risk.
By modifying the secondary coil on a MOT, the transformer is converted from a high voltage/low current device into a low voltage/high current metal melter. High current can be directed to one focused location to fuse sheets of metal together on contact.
Using some scavenged parts from the microwave in a previous project, as well as some wood panels and a few other accessories, we can make a fully functional Spot Welder that works well, and has some built in safety precautions!
The electrical power is high enough to turn a nail into boiling liquid iron.