As tough as a graphite epoxy bottom is, damage still happens.
Took a really hard smack on the Watauga River in TN last weekend damaging the edge.
Thought I would share how I repaired it.
Found that a really good patch can be made combining two parts JB Weld with one part Five Minute Epoxy. So hard and slick a cat can't scratch it and blends in beautifully.
Sanded and cleaned the damaged area and then filled with the patch, making sure to get under any edges where the their was any delamination. The initial set time was short enough that the loose glass edges could be mashed down eliminating any voids and only took a couple of hours in today's 90-degree heat to harden completely.