This is really weird, but I'm seeing it on two boats now, and thought I'd throw it out to see if anyone else has run into this. In short, fiberglass repair below the waterline using West System epoxy. On the repairs, followed the standard procedures for washing off amino blush using Scotch Brite pads etc. I have not had any adhesion issues of the paint to the epoxy, but on both boats, moored in different parts of the Chesapeake, have had substantially more marine growth, especially barnacles, on the spots where the repairs were made. One boat is painted with Micron CSC, the other with Trinidad SR. So we've got ablative and hard epoxy paints, both not performing as well over the repaired areas as the rest of the bottom. One of these repairs is on the bottom of the keel, the other is on the rudder, so I can't correlate sunlight exposure either. The only thing I've been able to come up with as a theory is that the multiple layers of old bottom paint on both boats is leaching out more toxic stuff for marine growth than the areas that were repaired a few years ago and only have a couple coats of paint. Thoughts anyone?