Duncan has taught elementary/middle school art, in Michigan, as well as university courses in Kentucky and Tennessee.

Isaac has been an artist-in-residence for Gallery 37/Archi-Treasures, Illinois, the Richard Hunt Studio Center, Michigan and with the Association of Visual Artist, Tennessee. Duncan has been nominated for the prestigious Joan Mitchell Foundation Sculpture Fellowship and NIKE private proposals. Isaac is a recipient of the Tennessee Arts Commission Individual Artist Fellowship for 2017.

Duncan was employed by John Henry Sculptor, Inc., where he was the crew supervisor, heavy equipment operator and assistant to internationally renown sculptor John Henry.  In mid-2008, Duncan purchased a warehouse and opened his Tennessee studio, Duncan Sculpture & Services, where he creates large scale sculpture and fabrication projects.  Other renown artists that have contracted Duncan Sculpture and Services are international artists Robert Stackhouse and Carol Mickett, Marlborough Artists Jonah Freeman and Justin Lowe, Chakaia Booker, and Mexican sculptor Victor Contreras.

Duncan large scale sculptures have been collected by Pyramid Hill Sculpture Park, Hamilton, Ohio, Georgia Institute of Technology, Georgia, Lexington Diagnostic Center, Kentucky, African-American Heritage Center, Kentucky, Columbia State College, Tennessee, City of Chattanooga, Tennessee, Erlanger Children’s Hospital Kennedy Outpatient Center and Le Domaine Forget, Quebec, Canada and numerous private art collectors.

Isaac is the Past-President of Mid-South Sculpture Alliance, a national non-profit organization which promotes a supportive environment for sculpture and sculptors. He sat on various art boards and committees; Sculpture Fields at Montague Park, and ArtsBuild. He presently sits on the International Sculpture Center and the Tennessee Arts Commission granting committees