H30 skeg repair
Flash-sand the whole area around the seam. You're not grinding, so go quickly, lightly, with a light disc. I use little 3" ones at 24 grit on a small air grinder (Harbor Freight: $19.99. Read my review of it there). Leave no bottom paint, flaking gelcoat, filler, 'glass or anything that looks rusty, sticky, stained, etc.
Wash in solvent. Lay up new 'glass over the affected area, even if it's not smooth and even-- just roll it out so you have no air voids and have good adhesion.
Once this is cured, flash-grind the edges to get them more of less flush with the surrounding surfaces. If you are still well low, short of where it should be, lay up more 'glass.
Once you are close, make up a putty using fiberglass resin and milled fibers (which are chopped-up fiberglass material). This won't sand easily, so trowel it on smoothly and with care. Then fair this with your sander again, getting it as fair as you can while reducing paper grit (increasing numbers).
This is exactly what I just did on the damaged Raider 33. I still owe it a little more fairing before the new application of Interprotect; but it's pretty close now.
I am presuming that you have checked the bolt ends inside the boat and found them solid, and that the skeg isn't loose against the hull but merely a little chipped-up and needing filler.
JC2
