Thinner wire has more of a tendency to hang up in the stinger and create problems unless the wire speed is carefully adjusted. Flux core wire is my least favorite- - - -it splatters sparks all over the place and the slag must be cleaned off the welds before priming or painting. I keep a small angle grinder with a stiff wire wheel on it handy for slag cleanup. Gas shielded bare wire makes a much cleaner weld that requires little if any cleanup before painting.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!