We're working on a #5 gold onlay, and I'm seriously stuck. I have the prep and impressions just fine, but I'm having a doozy of a time pouring casts that aren't riddled with bubbles. I'm vacuum mixing, spraying with debubbleizer, and holding against the vibrator plate as I fill the impressions with stone. In short, I don't have any idea what I'm doing wrong, but I've done it wrong three consecutive times now, and I don't want to fall behind. Any upperclassmen want to share your tricks for getting these things right?