For this question I am referring to a board bow with a glued on, multiple laminate, non bending riser. I have recently started using a dremel with a sanding drum to help fade my riser into the belly and must say it looks great, super smooth and exactly the way I want it. After the bow is all finished with thunderbird it looks great. However, after numerous shots with the bow I am beginning to see what looks like a glue line at my fades. Why is this happening and how do I prevent it?