Watch Frank's video on cutting open a propane tank, he uses an angle grinder and a cutting wheel. Unless I'm at the shop with the plasma cutter I do all my cutting with the angle grinder.
You will go through many wheels if you use cheap ones. Pay a little extra and get good quality wheels. I personally use Dewalt wheels and they seem to last very well.
If you do not have a plasma I would get that blue wrench out ie a torch with a small tip. I have cut several with a metabo too but Wow it kinda stinks!!!!!! If you do use cutoff wheels like Clover ridge said do not buy the cheap ones you will regret it!!!!!
I have a brand spanking new DeWalt 4 1/2" grinder and a bunch of cut off wheels of the same brand. I try and stay away from cheap tools if I can. You usually get what you pay for.....
I really prefer using a cutoff wheel....it provides a great cut and almost no clean up if you are steady. I chose to cut on the weld line on the end bell, so I was cutting almost 1/2" and it was perfect. I'm a relative newbie building smokers but hand tools are second nature in my business....just my two cents
I got the end of the tank cut off last weekend with cut off wheels. BUT, yesterday I pulled the trigger and bought a little Hobart plasma cutter. I intend to try it out today by cutting the diamond plate I got for the trailer deck.
i know i'm chiming in late here, but i too did my entire build* with a 15amp milwaukee 4.5" grinder and a pack of harbor freight cutting discs - which is how i also cut the end of the tank to mount the FB. i know, they are cheap discs, but i get a TON of life out of them, if you don't just bury the blade against the metal and let the tool do the work, they last plenty long.
* i did use my friends chop saw for a couple cuts but couldn't get a cut that wouldn't 'walk' on me so i stopped using it. used my sawzall for one cut, which proved to be a pain in the ass. used my milwaukee 4" cut bandsaw for cutting things as well, usually late a night when i didn't want to wake the neighborhood with the sound of screaming metal cutting.