I think this is what it is called. I built a Night Heron 4-5 years ago and I was very happy with the finished surface. I just finished fixing a crack in my deck (between the cockpit and rear hatch). I glassed and epoxied like I did when I built it but for some reason the fiber glass (a 3" x 10" piece I cut from a larger piece) has shown through the epoxy. I have completely filled in the glass with epoxy (4-5 coats) but still lightly see the hatching of the glass. Does anyone know why this occurred and how I can avoid it in the future?