Gronk was born in Los Angeles in 1957. He has credited graffiti and mural art in his East Los Angeles neighborhood as being some of the earliest inspiration for his art.
In the 1970's Gronk was a founding member of Asco, a multi-media arts collective based in Los Angeles , which was influenced by European film, existentialism, and literature. Asco gained early notoriety when he and fellow members Harry Gamboa and Willie Herron tagged their names on the Los Angeles County Museum of Art. The action was in response to being told that LACMA didn't collect Chicano art because it wasn't "fine art". Obviously, a situation that has changed over the years.