It is often said that to select the best impregnation process “let the parts talk”. Do these parts have a tight or difficult pressure test requirement? Are they limited by print to only one cycle of impregnation? Are they highly machined with tapped holes and/or small passages? Will they be immediately pressure tested and built-out into final assemblies after impregnation? All these factors will point toward choosing the best process.
Vacuumimpregnation generally follows the same four steps (see also animation by Godfrey & Wing):
With this understanding, there are three viable impregnation methods that can occur during the impregnation step:
Additional references: