Sorry, dude, I can't help you with that one... Oh, Ang, maybe you or Becca should take this one. [:0][}
]
There are just so many things I could have said, but I'll be nice... for once.
Assuming you are talking of Mercury, you can cast w/o vacuum. You CAN use vac for just a minute or so first thing, but pressure casting (about 30 PSI) will ensure that any bubbles will be indistinguishable.
In stabilizing I've been gotten good results w/20-27 inches. Pull a vacuum and let it sit for about 30 minutes; release the vacuum for about an hour and repeat these two steps as many times as you can over a day and a half.
Vacuum chucking I have not tried yet so I can't answer that one.