I bought a beer keg that had been converted into a brewing kettle. A twelve inch circle was cut into the top, and two holes were drilled near the bottom. A 1/2 inch NPT full coupling was welded into the two holes. One is for a ball valve to drain the kettle, and the other for a thermometer.

The kegs are type 304 stainless. The problem is, the welds on the couplings were poorly done. They were ground down too much, I think, and there's rust around them like maybe a mild steel wire wheel was used instead of a stainless one. But the main problem is that the keg leaks at the coupling weld.

I have a Hobart Handler 187 that I bought earlier this year. I've never welded and I haven't even plugged it in. I put off learning how to do it earlier this year due to a home remodeling project. But now that's done and I'm ready to start. I had a 230 volt circuit put in to my back porch. I just bought a bottle of C25 and a bunch of mild steel for my first project, which will be a beer brewing stand.

I'm thinking about trying to fix my keg kettle myself. I understand I need pure Argon for stainless. I'm wondering if I get a bottle of Argon and some stainless wire, how hard would it be for a rank beginner to fix those leaky welds on the 1/2 inch full couplings? How would I go about doing it without ruining the keg? Will the wire add enough material to the weld by itself to stop the leak? I'm not sure what gauge the keg metal is, but it's pretty thin compared to the 2 by 2 by .120 stuff (11 gauge) I bought today for my brew stand.

Or is this a job for a more experienced welder? I'd hate to ruin the keg, as they are fairly pricey. Still, I might give it a try if it doesn't sound too difficult.