Surfing Waves

Just got a board and there is a crack in the fibreglass on the tail end. There are no surf shops in town and i want to have it fixed before i head to the coast this weekend so i dont have to waste time looking for a shop to fix it. Are there any simple alternative methods of fixing a crack? I don't have time to order a kit and my only recourse is the hardware store. I was originally just going to cover it with some silicone rubber stuff but then i read some epoxy or resin stuff (i dont know which) can eat away at the foam or something, so, let me know.
Any help is very appreciated!

Namaste, Tapsi, this could be a challenge if you are based in India, please post a picture of your board and the damage.
We cannot advise you which resins to use without knowing whether your board is PU standard glass job or EPS foam with epoxy glass job.
If you go to your local beach there could be tubes of solar resin of either type available.
Polyester or epoxy.
Do not use polyester resins on EPS as your foam will dissolve. Hardware store will mostly only carry catalyst setting polyester resin and involves more work and skill and is messy
Get the appropriate solar resin smear it on so it is smooth and then place in the sun and 5 minutes later surf ready.
You still need to know your boards type of foam. So picture please.