be hard, I've used arc on thin stuff but that was just trying it out I don't own one myself so the only time I use it is under supervision in the workshop so wouldn't want to say but reckon with some thin rods and power ramped down you may get away with it ?
scrap the hire idea just looked up costs ,no point in buying a cheap small hobby one as it will be very hard to get any form of decent weld especially on thin stuff
Think it was only a 1.2mm wall as it was a tractor exhaust I had modified so just a straight stack
had to turn it right down but it was ok with it, done bodywork with a smaller one and that was a bit awkward to get right, nice on a large one as you have more choice