We typically recommend a 240V MIG welder but stick and TIG work as well. MIG is recommended because it's faster than TIG welding and it's cleaner than stick welding which means less grinding/sanding is required afterwards. However, all three methods are still totally suitable. You can still end up with a beautiful finished product with stick welding. Or, some guys have used TIG and then left the weld beads as is without any grinding which can look very cool. We generally recommend 240V, but especially recently, a lot of guys have been using 120V welders with great results. Welders have come a long way and many of the 120V welders out there are totally adequate for the 3/16" steel plate used for these bumper kits.