You can attempt a major repair, but it’s a serious project. For a snap, you need to align the stringer perfectly, glue it, and then re-glass the entire area. A massive rail crush or big gash requires significant foam shaping and multiple layers of glass. It’s doable with the right materials and a solid guide, but it’s easy to mess up the board’s flex and balance. For your favorite stick, a bad snap might be a job for the local shaper or repair guru.