Can you gelcoat over a very light fairing of marine grade filler? I was going the paint route, but have since decided that I may just gelcoat. After I repaired a few areas I used 3m premium marine vinyl ester fairing filler to ensure I had perfect transitions over my repairs. Now that I may be going the gel route, I want to make sure it is safe to use with gel.

It will work just fine. Both products are from the "ester" family.

I would prime and block it first to make sure you don't have any pin holes of sand scratches show thru