Harbor Freight sandblast cabinet stand and modifications

[PJs]

Congratulations Sossol! Thanks for the plumbing details and do like your Mid-Century Modern style and the USS Arizona plenum, Classy. The baffling seems appropriate inside your Arizona plenum. Tubing size should be ok at 2" depending on the motor/fan rating. The differential you are experiencing may be from the 90° elbows and possibly how far up into the cabinet the return protrudes, the grate and the height of the inlet. Maybe try a little filter paper at the inlet collection or a slide gate maybe to balance things out if the motor isn't an issue for you.

Great job and Congrats!!
PJ