Never welded with 100% Argon, but I weld steel all the time. 100% argon is used for welding aluminum. You use a 25% argon 75% CO2 mix for welding steel. All I can say is go get a truck load of scrap sheet metal from you local sheet metal shop, or any place that usese it. And weld it all into one big sheet. The shops will be happy to give it to you, and it is the best way to get better. You practice different thickness, angles, stright lines, curved lines. You do it all. And when you done you can cut it up and try again, or take it to the dump. The person on here to talk to is Crashyota, he'll tell you all u need to know.