Rollo or others:

I have recently completed a couple of gelcoat repairs on a metalflake bass boat. The center of the repair comes out pretty good but I'm not happy with the edges. I grind the area out and then apply black gelcoat before applying the clear and metalflake (all material applied manually with a brush, not with a spray gun). I appear to be seeing the outline of the black gel coat showing up around the edge of the repair.

Any advice on how to treat the "edge" of the repair area? Do I need to apply black gelcoat all the way to the edge or stop at some distance from the edge?

Also, when I initially grind out the area to be repaired, should I bevel the edges of the area to 45 degrees or 90 degrees, etc..?