Sculptor's inside say scraping away (7)
I believe the answer is:
eroding
'scraping away' is the definition.
'sculptor's inside say' is the wordplay.
'sculptor' becomes 'rodin' (Auguste Rodin was a French sculptor).
'inside' means one lot of letters goes inside another.
'say' becomes 'eg'.
'rodin' going inside 'eg' is 'ERODING'.
(Other definitions for eroding that I've seen before include "eating away" , "chipping away" , "Wearing away with time" , "Gradually wearing away, rock say" .)