Can anyone explain for me how they make really clean, crisp edges on hatches? I saw a fellow modelers (electric) F4D Skyray that had a radio compartment hatch that was almost invisible at the seperation line. Somehow after the cut he used filler and CA to build up the edge. He tried to explain it to me, but maybe I need to see it done visually to understand the technique. Do you know what I'm asking? Can you demonstrate it?