MIG welder much nicer welds than an ARC. TIG even better :insane: I've got a MIG welder, but my welding is rather crap. I did weld up all the rust on my car, so I guess I can weld, but I won't claim to be any good at it at all.
Most rust converters are very similar, they are pretty much some sort of acid. I'm using some stuff I got from Repco a little while ago, can't remember what brand it is now, but it seems to work. Don't get it on your hands, it's acid and it really stings! Or in your eyes, that's just all bad...