To start off:
Yes, we're replacing our tong-system for a crucible with hooks and poles 'n such, our welding guy just hasn't gotten around to it yet. Until then, we're taking all possible "not-dropping-it-and-flinging-molten-metal-everywhere" preventative measures, which mostly center around not dropping it.
Yes, we replaced our shoebox with something not made of cardboard immediately after this pour.
No, we didn't end up pouring into the plastic tub beside it instead.
So, now that all possible safety concerns have been addressed (yes, all possible), let's get to what else we learned.
Modeling clay. Useful for holding the shape of something. Loses this quality at the temperature of molten aluminum.
Modeling clay. Smells worse than literal shit at the temperature of molten aluminum.
2nd pour, not shown:
I carved some styrofoam into the shape of a basic case for a small piece of electronic gear. I then coated it in plaster, and let it dry.
Drilled 5 holes through it. Covered it in sand. Poured molten aluminum on top of it.
The styrofoam did a mostly impressive job of vacating the premises, but the aluminum did not make much progress on filling the void. I was left with a plaster shell locked onto a blob of aluminum with small bulbs of aluminum at each drill point.
Was the styrofoam itself holding back the aluminum just long enough for it to harden and halt its ingress? Do I need to burn out the styrofoam before the pour?
I believe the more likely explanation is that I had it laying horizontally, and was hoping the aluminum would flow that way. Do I need to try again with the exact same conditions, but nearly all flow in the vertical direction?
Am I misunderstanding anything fundamental about the lost-foam method?
Would things works just as well with a "lost-cardboard" method, or would cardboard leave too much behind while burning off? I imagine if it worked just as well it would be a thing I'd have heard of since cardboard would be easier to work with, but I figured I'd ask.