When I got back into casting, I had been using a dipper that was a coffee measuring scoop fastened to a handle. I thought it was Al, but didn't think it mattered. I never had a problem at the low temperatures I was using, but then I got a Lee four pound pot, which can get really hot. I made one dip, and came back with half a dipper! I didn't realize I could get it hot enough to melt aluminum. After that the melt in the pot was pretty but worthless; all kinds of different colors, and just big clumps that don't pour.
Wayne