After brief interludes in industry and a short-term relocation to France after his father's death, Gaudin returned to Columbia in 1924 as a lecturer. In 1926 he became an American citizen. From 1926 to 1929 he taught at the University of Utah, and served as its head of research working with the U. S. Bureau of Mines in exploring flotation reagents. From 1929 to 1939, he was initially the "first research professor in ore dressing" at the Montana School of Mines, Butte, and continued his work in flotation research.