Is it necessary to vacuum or pressure the Alumilite's clear and flexible resins?Updated a month ago

No. It is not required but is highly recommended to achieve castings with absolutely no air bubbles present within the cast piece as well as provide the best physical properties. Both of these materials start out at a higher viscosity (thicker) than the lower viscosity fast cure Alumilite resins. Therefore, when these two materials are mixed, air is introduced into the mix and the viscosity (consistency) of the material does not allow the air bubbles to freely find their way to the top of the cast piece before the material cures. These two materials feature a slightly longer open/work time in order for you to either vacuum and/or pressure cast to eliminate all of the bubbles within the casting.