Reddit mentions of Jones Stephens L42-006 Melting Pot

that cruciable is VERY small.... you want something bigger for sure. If its a backyard forge, and you are going to be melting aluminum, you can try a cast iron crucible. you can get one on amazon... they are sold as lead melting pots for making bullets. a 10lb lead pot will hold about 2+ lbs of aluminum. Cast iron works better than steel (like old fire extinguishers). Steel will leach into the aluminum and eventually your castings will get some rusting.

As to where to cast... think of what you have as a BBQ gril... a really really high powered BBQ. anywhere you can grill, you can cast :) as you arent burning wood (I assume you arent).

You could cast on your driveway/parking lot, but you should considder opening a 50lb bag of and and pouring it into a spot and putting your furnace directly on the sand, and then another bag spread out under your pouring area incase you have any spills, the sand will keep your driveway from exploding.

I would definately think twice about casting near the snow or water. if the metal COVERs some water/snow it will turn to steam and "explode" (not really an explosion, more the steam is projecting the molten metal). if you cleared the snow, and then poured down some fresh sand, you should have a pretty dry area to pour.

edit : here is a link to a 20lb lead pot, see if it will fit your furnace : http://www.amazon.com/Jones-Stephens-L42-006-Lead-Melting/dp/B000CNKFRI/ref=sr_1_4?ie=UTF8&qid=1452183743&sr=8-4&keywords=cast+iron+lead+pot

if its too big, they have 10 lb pots also.