I think at this point my biggest issue is actually my welder...let's just say it's not exactly a high-end unit. I've used a Hobart Handler before at an old job I worked at, and even though I'm
far from a professional welder talent-wise, the difference between those and the one I have is night-and-day. I bought my current one ~10 years ago, and really didn't know what to look for when I bought it.
I am using .023" wire right now which I purchased from a local welding store, and I'm using 75/25 shielding gas.
FWIW, all of my repairs have been butt-welds (tacked at 1" intervals to start, of course), I'm not a fan of lap joints for repairs like this, even though they're 10X easier to weld than a butt-weld.
( patiently awaits the silly comments re: "butt-welds"

)
I guess I just need to bite the bullet and step up to a nice Hobart, or maybe a Miller and put this thing out to pasture.
Eric