.023 is smaller wire and it is what you need to weld panels and exhaust. I would certainly recommend shielding gas over flux core. I have seen many people try to learn to weld with a flux core machine and get frustrated. If you get a good 110v mig and use argon/co2 mix, clean your metal and use a lens dark enough to shield your eyes but light enough to see what you are doing, you can learn to wire weld. Practice by welding scrap pieces the same thickness as your body panels. I have a Hobart 140 120v at home that I use for body panels up to 1/4". I have large welders at the shop up to 400 Amps. But the Hobart does everything I want to do on my jalopies at home.
