If you want to lam-up the trailing edge (which wouldn't be a bad idea if it's cracked), you need to:-
1./ Get all the antifoul off, and grind the gelcoat back to the grp mat, say for a couple of inches on each side.
2./ Get some close-weave glass tape or sheet (and cut it into strips). You want something about 200-300 gram
For the lay-up you'll need some polyester resin, and some filler (glass bubbles or microballoons)
3./ Glass 2 or 3 layers onto one side, so that it hangs over the back edge of the blade by about 10mm
4./ Mix some resin with glass bubbles until it becomes like toothpaste (too thick to run). You might need to add some silica to thinken it.
5./ With a wooden spatula (or you thumb) gently put a bead of this down the trailing edge, so you fill the gap that would otherwise be left between the 2 lams.
6./ Glass-up the other side with 2 or 3 layers of mat, making sure that you then push both sides firmly together at the trailing edge into the filler.
When all is set, cut the excess glass off the back with a cutting wheel and sand/grind back to a nice edge.
Then give it a good sandng flat, and give it a coat of flowcoat (geloat topcoat).
Job done.
One thing. Depending on how warm it is and how many people there are doing it, you might be advised to use a slow hardener.
