Delvene! Ernie's preparing some surface coating (6)
I believe the answer is:
veneer
'surface coating' is the definition.
'veneer' can be an answer for 'coating' (veneer is a kind of coating). I'm not sure about the 'surface' bit.
'delvene ernie's preparing some' is the wordplay.
'some' says the answer is hidden in the clue.
'VENEER' is hidden within 'delvene ernies preparing'.
Can you help me to learn more?
(Other definitions for veneer that I've seen before include "Thin superficial layer" , "Finish" , "Superficial polish" , "Thin layer glued to a surface" , "Thin skin on surface" .)