I bought a Century wire feed welder at Wally world uses Lincoln flux core wire 0.035 dia.
It works good only down side is you are more likely to have burn through holes when welding thin gauge metal. Something else is the weld will need cleaned as the flux core wire is messy. It will have slag and splatters that will need to be cleaned off.
I prefer O/A gas welding for the thin stuff.
For the price of the Harbor freight welders when on sale you can't beat the price. I don't think you will see a professional welder using one to make a living. But for the hobbyist welder they should be good.