weilding pre-shtf i can make vertually anything i want, giving theres enough scrap metal to go around, post-shtf, not much untill true homesteading begins and people quit looting and killing everything in sight. an ARC weilder uses 220 electricity, its kinda like hooking up battery cables except in the positive side you have your rod, then use the electricity to melt the rod. but post-shtf 220 will be hard to come by untill we make alternative electricity. However there is the MIG weilder that runs off of the standered 110 electricity (the regular plugs in a house) and runs wire feed instead of the rod, which i would recomend to beginners (you can buy them at harbor freight for around $100) the MIG is used for smaller weilds, like sheet metal or thin metals that an ARC would burn right through.