I have used epoxy putty from Lowes/HD to rebuild a cracked ski. 5 years later, still perfect. Just pushed it into the grooves, gave it 5 minutes to set, sanded it down and covered it with a little dark paint to blend it. You almost couldn't see the repair unless I showed it to you. This was for a CDX with a tail crushed in shipping.
Previous: 1993 Prostar 205
Red 1998 Ski Nautique, PCM GT40, 310 hp, , Acme 4 blade, Perfect Pass SG/Zbox.
Be kind. Have fun.