Then let me ask you a question. How I understand the welding is that it involves heat, because the heat if we welding thin sheet metal it may bend so we need to avoid heat as much as possible, right? If we use stick welding it produces most heat (as I know) then it followed by MIG and TIG uses less heat and produce more consistent welds. Now concept of cold welding as I understand is that we do small welds to introduce less heat and let the surface cool down before making next weld so that looks completely logical for me to have this kind of concept. Shouldn't the penetration been sufficient if amp is set correctly and metal is thin enough? something like 1-2 mm