Abstract: A preformed body (12) from powder material of metallic and nonmetallic compositions and combinations thereof, is consolidated to form a densified compact (12") of a predetermined density. An outer container mass (20), capable of fluidity in response to predetermined forces and temperatures and which is porous to gases at lesser temperatures and forces than said predetermined force and temperature, surrounds an internal medium (22). The internal medium encapsulates the preformed body (12) within the container mass (20) and is capable of melting at the lesser temperatures to form a liquid barrier to gas flow therethrough. The internal medium (22) is capable of rapid hermetic sealing during the early stages of preheat. External pressure is applied by a pot die (16) and ram (14) to the entire exterior of the container mass (20) to cause the predetermined densification of the preformed body (12) by hydrostatic pressure.