I am new to welding and I would greatly value your help.
I have a Hobart Handler 175 MIG (220 V) that takes 0.030" wire and I have a tank of the common AR/CO2 shielding gas (not sure what the exact mixture is).
Can a car frame made from 10 gauge (0.10x") mild steel be safely welded with this setup?
Some of the welds I want to make are only for additional stiffening such as welding up some seams that the factory skipped to save money and adding some gussets. However, one weld is truly "mission critical".
Is it important that I pick the right alloy wire, or are all wires intended for mild steel more or less the same? (One roll I have is Alloy E70S6 Heat 1566FI. Another is Spec. AWS A5.18 Heat 5111422.)
Is there anything in particular I should watch out for? For example, heating the area too much and accidentially causing a brittle crystalline structure (martensite) or anything like that?
Since I am new to welding, I am thinking about farming out the mission critical weld. I got quoted $150 for doing just that one. It is a bracket that holds a control arm to the frame, so if that weld fails it could be very bad news...
Thank you much!