I understand that most modern investments contain wetting agents
that are supposed to minimize or eliminate the need for a
debubblizer when vacuuming during the investment process. My
students and I have done a lot of work where we vacuum twice--once
in the bowl after mixing and again after pouring into the flask.
Yes modern investments have wetting agents in them. I used to manage
a small production casting shop where we did at least 18-20 4" x 9"
flasks a day. Each flask had 20 to 100 or more parts in it. We used
several different investments while I was there R&R Ultravest,
SatinCast 20, WestCast they all were mixed and degassed with a
vacuum and no debubbleizer was used. Bubbles were very rare
James Binnion Metal Arts