I'm working on a project for work and need to fill a 55-gallon drum half way and maintain it at 180°F. Right now I was thinking on using dishwater heating coil. Typically how much voltage does one of these need to run? Does it vary by brand?
If uniformity of temperature is important you will need a stirrer of some sort.
Good thermal insulation around the drum will help with the uniformity issue and to minimise power consumption.
What will fill the drum?
If smaltz is gloop, then I would go for placing the drum on a hot plate and fix a contact thermostat to the outside, then the inside can be cleaned without obstruction
A hot water immersion heater close to the bottom with a built in thermostat would do the job but would be difficult to clean out.