If his sole purpose is farming, you'll want to be using AE. Find a "CEBR"* mission in AE search, and run that until you hit 32-33, which should really only take an hour or so if you're already 18 (assuming no lag). After that, you can probably switch to fire ambush farms and go at a faster pace because of burn/footstomp. That should then take maybe 2-3 hours to hit 50.
*CEBR stands for "Claws/Electric Brutes Rule" and is a mission architect them in some low level farming missions which allow you to farm VERY effectively at lvl 1 with nothing but a damage aura and any attacks you can get before lvl 6. Set to x8 with bosses and insp up with 4 purples, 9 oranges, and as many reds as you feel necessary, then jump into the mish and gain xp.
Thanks for the advice, that really helped a ton. I will hopefully hit 50 on him very soon.
Just be sure to use the insps rapidly with the F1-F4 keys and click buy at the same time on your mouse, it saves time and keeps them on longer in the mish. The insp vender is to the left of the mish entrance when you are facing it from the computers.
I'm working on leveling a farmer that's SS/Fire as stated in the subject. My main problem is that I am having all kinds of difficulty getting through some farm missions to level him. He's only 19 at the moment so his AoE damage is limited to only Blazing Aura right now. Should I craft a temp power or something to use until I can get burn to help kill things faster? Or is there something I may be doing wrong?