I've had this happen on my Kitfox SLSA it was on the right flaperon. It did start separating. I sanded re-epoxied and had to go with a rounded head rivit wher the rivit pulled out. I added two additional digits on doth sides of the rivit that pulled out. On preflight a, I now inspect between each of the rivets to check for delamination. When I was flying out to the 2015 Kitfox Factory Flyin I noticed it while unpacking in Abilene, Texas. I got socked in in Abilene with fog, I did a temp fix and when the weather cleared I flew home.