Wire Arc Additive Manufacturing (WAAM) is a metal 3D printing technology that rapidly prototypes by depositing molten metal wire onto a substrate. Traditionally, WAAM has relied on open-loop control with carefully tuned parameters, a process that can be time-consuming and often results in inconsistent performance. Although laser line scanners and other 3D scanning techniques have been used to ensure geometric fidelity, they typically provide feedback through layer-by-layer scans, leaving imperfections from arc striking and extinguishing. This paper introduces a novel approach incorporating infrared (IR) camera thermography to achieve more consistent and reliable WAAM printing with real-time feedback. By using IR live streaming to close the loop with in-layer updates, we demonstrate how this feedback mechanism can enhance control over bead width consistency and wire stick-out length, ultimately leading to higher-quality metal 3D-printed structures. Compared with open-loop preset constant welding parameters on a triangular wall geometry, our IR-guided WAAM process achieves 49% bead width variance reduction and 95% wire stick-out length tracking improvement.