If you do any metal work projects there will come a time when you would like to bond some metal together without using mechanical fasteners. Easiest way to do this is by welding, a spot welder is a type of welder that is simple since there are no welding rods needed. Make it Extreme built this great looking DIY unit. A high current is simply passed through the two metals in one spot allowing them to heat up and fuse together. Best of all the main component that is used is a MOT (microwave oven transformer), these can be scavenged from a discarded microwave for free. The main portion of the build is the structure that allows the unit to be free standing and operated by a convenient foot pedal.