Anthony - "minutes to get to SS temps?" My oven EvenHeat KF18 with 220 vac coils will get up to 1500ºF range is well less than an hour - perhaps 45 minutes? To get to SS temps in the 1950ºF range along with the 4 fire bricks I have laying in bottom of oven to put blades up next to TC tip, AND it helps oven to level out in temp better also.... I'd guess it takes darn close to 2 hrs for leveling out. Without the 4 fire bricks it will get to 1950ºF in a bit over an hour, but then needs to sit there cycling for another 15 to 20 minutes or so to level out, so the total heat up time isn't much difference with or without the firebrick. With firebrick there is enough mass inside oven the temps don't drop so bad when putting blades in or removing blades.
As Tracy says, "IF" you can possibly swing 220vac, even with using an extension cord, I wouldn't recommend 120vac at all.
Ken H>