A natural convection molten salt loop was designed, operated, and decommissioned to help revitalize experimental work with molten fluoride salts after nearly 40 years. Studying the salt LiF − BeF2 , the UW NCFL employs 80 thermocouples, six novel fiber temperature sensors, and develops a time-of-flight flow meter to study the flow field in great detail. The results highlight several flow features common in molten salts, including extreme temperature gradients andstrong mixed convection heat transfer. Qualitative descriptions and several data tables are compiled to aid future modelling or simulation efforts. A detailed analysis of the data shows that molten salt heat transfer is well predicted as developing laminar flow. Enhanced heat transfer occurs in horizontal flows due to mixed convection, while heated vertical flow is less impacted. Literature suggests cooling may enhance heat transfer by creating turbulent behaviour at low Re and a horizontal air cooler is also studied. Results agree well with mixed convection flow predictions and highlight the challenges ofmeasuring wall temperatures in the presence of freezing salt. As a final analysis, impurity concentrations are reported and the loop is cut apart for future study of thermal-gradient corrosion. Impurity analysis shows chromium and iron were present in the salt, possibly sourced from the heated tubing. Cutting open the loop reveals metallic deposits in the air cooler and unexpected growths in the heaters that may have obstructed flow.