Ok, total neophyte input here on my part. But most of
the
techniques I've seen involve doing the casting inside a small
dixie cup. If the problem is air bubbles, what about using a
common (at least back in the 70's) device that many people
still have in their kitchens... a "seal-a-meal". Mine has a
I think the usual approach is a vibrating table shake the bubbles to the
surface.