High vacuum chamber

Weldling; avoid dirt accumulation nooks and crannies, weld from inside full depth ( i.e. not both sides leading to trapped internal air pocket).

For sub 15µ powder use optional atmospheric pressure (1 Bar) arm glove entry lockable port holes, for sand blast & suction/vacuum cleaner clean up (using metal powder not sand in blaster & Vacuum cleaner) Sieve metal back to metal powder hopper from vacuum cleaner.

Special case of active metals i.e.Titanium, Nitrogen reduced oxygenated cleanup.

Use airlock for build while pump down contained in vacuum chamber door,

Further reading ; Vacuum chamber principles; Essential reading before you weld/construct your vacuum chamber, Basic Vacuum technology by Varian