I'm going to put 9 layers of glass on the top and 9 on the bottom, for a total of 18 layers. That'll be about 3/8" or thicker. The longest layer is about 7" long, and the shortest is about 2" long, to match the bevel I made to either side of the puncture. I'm going to use epoxy resin rather than polyester, because it forms a stronger mechanical bond to old laminate. Using epoxy means I might not be able to put gelcoat over it, but I don't care about that since it will be hidden under the rubrail.