wirefeed thickness, max thickness?

Now that I´ve learnt the minimum thickness for solid and fluxcore wire, what would you say is the maximum sheet thickness I can attack with my 100 amp mig? At the moment it has 0.03" fluxcore, but I also have a spool of solid 0.035 wire, plus of course(?) I could get some thicker wire. Havent checked how thick the feeder will handle. Btw you often mention machines running on 110 or 220 volt. To me thats not saying very much. What kind of amperage are we talking about? Henning