How fine was the sandpaper? With very fine sandpaper, the finish is so smooth there is nothing to grip to. I am sanding hulls for repainting and will use 80 grit as final sandpaper before painting.
Get the shape you want with 80 to 100 grit. Epoxy. Final sand with 220 to 320 grit.
Are you mixing the resin and hardener correctly? Buying the pump system is worth the money.
John
P-19
