Mild steel, mostly under half-inch. Basic farm equipment fabricating and repair. I have lots of 1/2" plate and what looks like maybe 1/4" plate that is somewhat rust-pitted but serviceable. Also mild steel pipes of various sizes, angle iron various sizes and some light-weight steel in a "C" shape. Also aluminum pieces of this and that. And don't get me started on how much thin corrugated roofing sheets there are! Yeah, I'm looking at MIG down the road.

It is by no means a production/industrial use, so I just don't see getting into plasma (but dang!).

I've got a pretty good Miller (Bobcat) welding machine on semi-permanent loan from an in-law who's getting on in age and has been teaching me stick welding. I'm competent at butts and fillets and am learning how to weld in a vertical bead, but it looks like a bad case of dribbling diarrhea, so I have a way to go on that. I have 40# of 7014 sticks and a couple of tons of steel and I'm retired.....

I've been thinking about OA because in farming there's lots of cast parts. OTOH, I watched my in-law stick weld a couple of mild steel straps onto a broken cast piece (where the tie rod end attaches to the hub, the point of attachment was broken) and it's holding up just fine nd will likely serve until the factory sends me a whole new piece (under warranty and they admitted the design is defective and are redesigning it, so replacement part is on loooong back-order).

My only experience with cutting has been with propane and I am competent with that. I just don't like limiting options through my own ignorance.