Vacuum bag layup process

[Deuelly]

I noticed on the Raptor aircraft videos that their vacuum bagging process is two steps. The 1st step is the outer skin and the core. The 2nd step is the inner skin. On other videos I've seen most people seem to vacuum bag the outer skins, inner skins, and core all in one step. Is there a certain reason for one process over the other?

 

[wsimpso1]