Bumpy cast

Dear Orchidians:

Yesterday we casted a cylinder with silver, today, when we extracted
it from the investment, some stones were out of their places and the
cast was all bumpy, like if the waxes had a lot of little bubbles of
air when invested.

We used the vacuum investment mixer and washed our waxes prior to
invest, but the outcome is as I explained.

Can anybody help me?

I will appreciate it much.
Best regards,
Juan Pablo Martenez Mansilla