Hey Ken, that's a pretty large crucible. You may be under filling it to save on the charcoal materials.
Consider making up smaller crucibles out of black pipe or thick wall square tubing. It's not a big deal to weld a flat base on the bottom, and rig up a slip fit welded square cover, or use a die grinder to clear out the threads of a screw on cap for round pipe.
I think I've mentioned before that you can cut V's off of angle iron quickly with a chop saw and weld them to the sides where ever you want so the crucible doesn't slide with whatever you hold it with. You can burn off paint and oil with a torch before you run it in your kiln.
I think fill the crucible, tap it down, and fill some more in. Careful this time of year, there's a bunch of CO produced that might not be venting off.
