You are seeing the result of water that has penetrated the barrier coat / fairing.
- Use an orbital sander and sand the area down to reach the lead.
- Make sure all the areas on the edge are well bonded to the lead
- Feather the edges about 2 inches so there is no bottom paint, just the barrier coat and fairing
- Score the lead using a stiff wire brush
- Mask around the area
- mix unthickened neat epoxy and use the wire brush to work it in the scored lead
- tape release cloth over the area, squeegee smooth and let cure
- peel release cloth when cured and wash with plain water to remove any amine blush
- dry and light sand with 80 grit paper to rough up cured epoxy - hand sand so you don't burn through, then wipe clean with acetone
- apply Interprotect 2000e barrier coat - one coat and let cure
- If there are any low spots fair with epoxy thickened with microlight fairing compound and let cure
- sand with 80 grit and wipe clean with acetone
- apply 3 layers Interprotect 2000e - you can follow the timing using the thumbprint test for recoat.
- apply bottom paint within the time limit for thumbprint test, or later which requires light sanding.
ps - I entered you in the fleet database. You can access your record when logged in to the forum by clicking on your user name, then click View Profile. Click Class Database Link next to J/30 Profile. You can update information there.