centerboard

I am repairing my centerboard. ~ 1" of the front edge at the bottom was missing (as if someone had driven it down the road with the centerboard down). I've built that up with epoxy and filler from west marine, and sanded it back to shape. The clerk at west marine told me I could spray gelcoat on top of that if it's well cured. Is this correct or is there another step to assure a good bond? Also while racing last summer the locknut came off of the centerboard roller and one of the rollers fell off ( Ihad replaced the bolt which was bent and not gotten the locknut far enough on) If the bolt had slipped out all the way would I have lost the centerboard? Or are the tolerances such that the centerboard would have hung up in the lower centerboard trunk? Mark