The present technique provides a system and method for improving atomization in a spray coating device by internally mixing and breaking up a desired coating fluid prior to atomization. In one embodiment, a flow barrier is disposed in the spray coating device downstream of an internal fluid valve and upstream of a fluid exit. The flow barrier may have a plurality of passages configured to direct fluid streams to create a fluid swirling and rotating motion around a central axis of a central flow path to facilitate fluid mixing and breakup. The plurality of passages may direct the fluid streams toward a surface, and may be angled substantially toward one another or diverging from one another. Embodiments of the spray coating device may further include an atomization mechanism adapted to facilitate formation of a spray of the fluid flowing from the fluid exit. The resulting spray coating has refined characteristics, such as reduced mottling.