An associative ring R with identity is called f-clean ring if every element in R is the sum of an idempotent and a full element. In this paper, various basic properties of f-clean rings and f-clean elements are proved. Also, we give some new charaterizations of f-clean rings. In addition, we prove that the ring of skew Hurwitz series T = (HR, σ) where σ is an automorphism of R is f-clean if and only if R is f-clean.