I like the lepage stuff that comes in a syringe. It's two tubes meeting at one nozzle. You squeeze the two parts out onto a piece of plastic, or into the core of the board, use a toothpick to mix the epoxy REALLY well, then rest the board in a position that will allow the epoxy to sort of sit in its final position.
Generally the stuff is quite liquid when working with it, so you want to make a cavity for it to fill, then pour it in and let it cure. Then you can sand, file, shave it down and paint if need be. I repaired board this way in the mid-90's and it's still holding up.