Serl befriended stars and curators as readily as runaways. He married and divorced three times and had two children. After World War II, he moved to the California desert, where he collected objects from garage sales and flea markets. When he moved to San Juan Capistrano in 1949, he started painting with homemade pigments and oil paint he applied to found boards, Masonite, and canvas, as well as to discarded paintings. He created more than 1,200 works featuring wide-eyed, slim figures with bendy limbs reminiscent of the work of Edvard Munch. Incredibly self-sufficient, he took up gardening, grew his own crops, and raised chickens. He refused to exhibit his work until the 1970s and often did not cash checks for the sale of his work, mounting them instead on his kitchen wall. In 1970, the Municipal Arts Department of Los Angeles toured an exhibition of forty-one of his paintings. Calvin-Morris Gallery became his New York dealer. In 1971 Serl moved to Lake Elsinore, in Riverside County, California, where he lived until his death.