I am hoping to refinishing a tool chest by removing the paint and rust and applying new "rust-proof" paint. I have tried sanding by hand which works very well on the rusted areas but it is slow on the painted areas. I have tried using a random orbital sander with worse results than doing it by hand. I am using 80-100 grit sandpaper made for use on metals and am having no luck.
Any ideas on how to speed this project up?
I like the sand blasting idea but have no idea where to go to get this done, any resources? I will also try the wire brush, I'll let ya know what happens with the brush.

Wire Brush.

If any uneven spots, you can use "all purpose putty" from lowes or home depot.