Carbon nanotube network (CNTN) devices are useful in integrated circuits and display drivers, particularly in applications that make use of thin film transistors (TFTs) on flexible or transparent substrates. However, in such CNTN devices, the performance is usually limited by high electrical and thermal resistances at the inter-tube junctions. In this study, we present a novel method to improve such resistances by depositing metal at highly resistive inter-tube junctions using a localized chemical vapor deposition (CVD) process. We induce nanometer scale heating at CNT junctions by passing currents through the CNTN. This is done in the presence of metal CVD precursors in a vacuum environment, enabling the selective deposition of metal to nanosolder the inter-tube junctions. We show that the effects of nanosoldering are dependent on the metal workfunction, and that our nanosoldering technique can effectively improve the overall device performance by more than an order of magnitude.