Jamey:
As previous post said, I too used glass cloth and unraveled strands for my coaming. Granted it took a little time (1/2 hour for two cockpits). But it was free, epoxied out clear as can be and looked great. Also as a prior post said that they would just use a fillet... I don't think a opaque filled bead would do much for the esthetics of a boat that I'm sure that you are trying to make look good.

DAVE