For the investment to have the proper consistence it must be mixed precisely. Here I am weighing the investment powder and measuring the vol. of 100 degree F water. From the time you add the investment to the water you have 9 minutes to get the investment into the flask. I use a count down timer and divide the time as follows.

3 minutes mixing
3 minutes in the vacuum chamber to draw all the air out of the mixed investment
1 minute using a soft artist brush paint the patterns with investment to assure it covers all the nooks and crannies then gently pour the flask full.
2 minutes vacuum the filled flask again to assure all the air is out of the investment.

You want to avoid air bubbles clinging to the wax patterns at all cost. They will destroy your pattern.

I use a flexible rubber bowl to mix the investment in, I just let any excess dry and it falls out when you flex the bowl. Washing wet investment down your drain is a no no. It will collect in your trap and cure. That’s a drain stoppage Drain-O won’t touch. LOL

BTW yes the investment looks just like Plaster of Paris, it has just been formulated to survive the burn-out temperatures.